diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
index 4be0f9f..cf25003 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
@@ -1490,7 +1490,7 @@
 
                 if (!SettingHyperlink)
                 {
-                    if (Style.Font.FontColor == worksheet.Style.Font.FontColor)
+                    if (Style.Font.FontColor.Equals(worksheet.Style.Font.FontColor))
                         Style.Font.FontColor = XLColor.FromTheme(XLThemeColor.Hyperlink);
 
                     if (Style.Font.Underline == worksheet.Style.Font.Underline)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/RichText/XLRichText.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/RichText/XLRichText.cs
index 7ba0581..700ca98 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/RichText/XLRichText.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/RichText/XLRichText.cs
@@ -19,7 +19,7 @@
             VerticalAlignment = defaultFont.VerticalAlignment;
             Shadow = defaultFont.Shadow;
             FontSize = defaultFont.FontSize;
-            FontColor = defaultFont.FontColor;
+            FontColor = new XLColor(defaultFont.FontColor);
             FontName = defaultFont.FontName;
             FontFamilyNumbering = defaultFont.FontFamilyNumbering;
         }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Internal.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Internal.cs
index 9a7b489..2906e32 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Internal.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Internal.cs
@@ -15,40 +15,49 @@
             {
                 this.ThemeColor = defaultColor.ThemeColor;
                 this.ThemeTint = defaultColor.ThemeTint;
+                hashCode = 7 ^ themeColor.GetHashCode() ^ themeTint.GetHashCode();
             }
             else if (defaultColor.ColorType == XLColorType.Indexed)
             {
                 this.Indexed = defaultColor.Indexed;
+                hashCode = 11 ^ indexed;
             }
             else
             {
                 this.Color = defaultColor.Color;
+                hashCode = 13 ^ color.GetHashCode();
             }
+            HasValue = true;
         }
         internal XLColor()
         {
             HasValue = false;
+            hashCode = 0;
         }
         internal XLColor(Color color)
         {
             Color = color;
+            hashCode = 13 ^ this.color.GetHashCode();
             HasValue = true;
         }
         internal XLColor(Int32 index)
         {
             Indexed = index;
+            hashCode = 11 ^ indexed;
             HasValue = true;
         }
         internal XLColor(XLThemeColor themeColor)
         {
             ThemeColor = themeColor;
             ThemeTint = 1;
+            hashCode = 7 ^ this.themeColor.GetHashCode() ^ themeTint.GetHashCode();
             HasValue = true;
         }
         internal XLColor(XLThemeColor themeColor, Double themeTint)
         {
             ThemeColor = themeColor;
             ThemeTint = themeTint;
+            hashCode = 7 ^ this.themeColor.GetHashCode() ^ this.themeTint.GetHashCode();
             HasValue = true;
         }
     }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Public.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Public.cs
index 8346162..4da1d2c 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Public.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/Colors/XLColor_Public.cs
@@ -10,20 +10,30 @@
     {
         public Boolean HasValue { get; private set; }
 
-        public XLColorType ColorType { get; private set; }
+        XLColorType colorType;
+        public XLColorType ColorType {
+            get
+            {
+                return colorType;
+            }
+            private set
+            {
+                colorType = value;
+            }
+        }
         private Color color;
         public Color Color 
         {
             get
             {
-                if (ColorType == XLColorType.Theme)
+                if (colorType == XLColorType.Theme)
                 {
                     //if (workbook == null)
                         throw new Exception("Cannot convert theme color to Color.");
                     //else
                     //    return workbook.GetXLColor(themeColor).Color;
                 }
-                else if (ColorType == XLColorType.Indexed)
+                else if (colorType == XLColorType.Indexed)
                 {
                     return IndexedColors[indexed].Color;
                 }
@@ -35,7 +45,7 @@
             private set
             {
                 color = value;
-                ColorType = XLColorType.Color;
+                colorType = XLColorType.Color;
             }
         }
 
@@ -60,7 +70,7 @@
             private set
             {
                 indexed = value;
-                ColorType = XLColorType.Indexed;
+                colorType = XLColorType.Indexed;
             }
         }
 
@@ -87,7 +97,7 @@
                 themeColor = value;
                 if (themeTint == 0)
                     themeTint = 1;
-                ColorType = XLColorType.Theme;
+                colorType = XLColorType.Theme;
             }
         }
 
@@ -112,53 +122,43 @@
             private set
             {
                 themeTint = value;
-                ColorType = XLColorType.Theme;
+                colorType = XLColorType.Theme;
             }
         }
 
         public bool Equals(IXLColor other)
         {
-            if (ColorType != other.ColorType)
+            var otherC = other as XLColor;
+            if (colorType == otherC.colorType)
             {
-                return false;
-            }
-            else
-            {
-                if (ColorType == XLColorType.Theme)
+                if (colorType == XLColorType.Color)
                 {
-                    return this.ThemeColor.Equals(other.ThemeColor)
-                        && this.ThemeTint.Equals(other.ThemeTint);
+                    return color == otherC.color;
                 }
-                else if (ColorType == XLColorType.Indexed)
+                if (colorType == XLColorType.Theme)
                 {
-                    return this.Indexed.Equals(other.Indexed);
+                    return themeColor == otherC.themeColor
+                        && themeTint == otherC.themeTint;
                 }
                 else
                 {
-                    return this.Color.Equals(other.Color);
+                    return indexed == otherC.indexed;
                 }
             }
+            else
+            {
+                return false;
+            }
         }
         public override bool Equals(object obj)
         {
             return this.Equals((XLColor)obj);
         }
 
+        int hashCode;
         public override int GetHashCode()
         {
-            if (ColorType == XLColorType.Theme)
-            {
-                return ThemeColor.GetHashCode()
-                    ^ ThemeTint.GetHashCode();
-            }
-            else if (ColorType == XLColorType.Indexed)
-            {
-                return Indexed;
-            }
-            else
-            {
-                return Color.GetHashCode();
-            }
+            return hashCode;
         }
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLAlignment.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLAlignment.cs
index 3afb559..468ca03 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLAlignment.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLAlignment.cs
@@ -263,16 +263,17 @@
 
         public bool Equals(IXLAlignment other)
         {
+            var otherA = other as XLAlignment;
             return 
-               this.Horizontal.Equals(other.Horizontal)
-            && this.Vertical.Equals(other.Vertical)
-            && this.Indent.Equals(other.Indent)
-            && this.JustifyLastLine.Equals(other.JustifyLastLine)
-            && this.ReadingOrder.Equals(other.ReadingOrder)
-            && this.RelativeIndent.Equals(other.RelativeIndent)
-            && this.ShrinkToFit.Equals(other.ShrinkToFit)
-            && this.TextRotation.Equals(other.TextRotation)
-            && this.WrapText.Equals(other.WrapText)
+               horizontal == otherA.horizontal
+            && vertical == otherA.vertical
+            && indent == otherA.indent
+            && justifyLastLine == otherA.justifyLastLine
+            && readingOrder == otherA.readingOrder
+            && relativeIndent == otherA.relativeIndent
+            && shrinkToFit == otherA.shrinkToFit
+            && textRotation == otherA.textRotation
+            && wrapText == otherA.wrapText
             ;
         }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLBorder.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLBorder.cs
index a5656fe..bc21b53 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLBorder.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLBorder.cs
@@ -17,15 +17,15 @@
             if (defaultBorder != null)
             {
                 leftBorder = defaultBorder.LeftBorder;
-                leftBorderColor = defaultBorder.LeftBorderColor;
+                leftBorderColor = new XLColor(defaultBorder.LeftBorderColor);
                 rightBorder = defaultBorder.RightBorder;
-                rightBorderColor = defaultBorder.RightBorderColor;
+                rightBorderColor = new XLColor(defaultBorder.RightBorderColor);
                 topBorder = defaultBorder.TopBorder;
-                topBorderColor = defaultBorder.TopBorderColor;
+                topBorderColor = new XLColor(defaultBorder.TopBorderColor);
                 bottomBorder = defaultBorder.BottomBorder;
-                bottomBorderColor = defaultBorder.BottomBorderColor;
+                bottomBorderColor = new XLColor(defaultBorder.BottomBorderColor);
                 diagonalBorder = defaultBorder.DiagonalBorder;
-                diagonalBorderColor = defaultBorder.DiagonalBorderColor;
+                diagonalBorderColor = new XLColor(defaultBorder.DiagonalBorderColor);
                 diagonalUp = defaultBorder.DiagonalUp;
                 diagonalDown = defaultBorder.DiagonalDown;
             }
@@ -288,19 +288,20 @@
 
         public bool Equals(IXLBorder other)
         {
+            var otherB = other as XLBorder;
             return
-                   this.LeftBorder.Equals(other.LeftBorder)
-                && this.LeftBorderColor.Equals(other.LeftBorderColor)
-                && this.RightBorder.Equals(other.RightBorder)
-                && this.RightBorderColor.Equals(other.RightBorderColor)
-                && this.TopBorder.Equals(other.TopBorder)
-                && this.TopBorderColor.Equals(other.TopBorderColor)
-                && this.BottomBorder.Equals(other.BottomBorder)
-                && this.BottomBorderColor.Equals(other.BottomBorderColor)
-                && this.DiagonalBorder.Equals(other.DiagonalBorder)
-                && this.DiagonalBorderColor.Equals(other.DiagonalBorderColor)
-                && this.DiagonalUp.Equals(other.DiagonalUp)
-                && this.DiagonalDown.Equals(other.DiagonalDown)
+                   leftBorder == otherB.leftBorder
+                && leftBorderColor.Equals(otherB.leftBorderColor)
+                && rightBorder==otherB.rightBorder
+                && rightBorderColor.Equals(otherB.rightBorderColor)
+                && topBorder==otherB.topBorder
+                && topBorderColor.Equals(otherB.topBorderColor)
+                && bottomBorder==otherB.bottomBorder
+                && bottomBorderColor.Equals(otherB.bottomBorderColor)
+                && diagonalBorder==otherB.diagonalBorder
+                && diagonalBorderColor.Equals(otherB.diagonalBorderColor)
+                && diagonalUp==otherB.diagonalUp
+                && diagonalDown==otherB.diagonalDown
                 ;
         }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFill.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFill.cs
index 124475e..ac04541 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFill.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFill.cs
@@ -100,8 +100,8 @@
             if (defaultFill != null)
             {
                 patternType = defaultFill.PatternType;
-                patternColor = defaultFill.PatternColor;
-                patternBackgroundColor = defaultFill.PatternBackgroundColor;
+                patternColor = new XLColor(defaultFill.PatternColor);
+                patternBackgroundColor = new XLColor(defaultFill.PatternBackgroundColor);
             }
         }
 
@@ -125,9 +125,8 @@
         public bool Equals(IXLFill other)
         {
             return
-            this.BackgroundColor.Equals(other.BackgroundColor)
-            && this.PatternType.Equals(other.PatternType)
-            && this.PatternColor.Equals(other.PatternColor)
+                patternType == other.PatternType
+            && patternColor.Equals(other.PatternColor)
             ;
         }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs
index 96b5fda..dfb7174 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs
@@ -27,7 +27,7 @@
                 verticalAlignment = defaultFont.VerticalAlignment;
                 shadow = defaultFont.Shadow;
                 fontSize = defaultFont.FontSize;
-                fontColor = defaultFont.FontColor;
+                fontColor = new XLColor(defaultFont.FontColor);
                 fontName = defaultFont.FontName;
                 fontFamilyNumbering = defaultFont.FontFamilyNumbering;
             }
@@ -268,17 +268,18 @@
 
         public Boolean Equals(IXLFont other)
         {
+            var otherF = other as XLFont;
             return
-                   this.Bold.Equals(other.Bold)
-                && this.Italic.Equals(other.Italic)
-                && this.Underline.Equals(other.Underline)
-                && this.Strikethrough.Equals(other.Strikethrough)
-                && this.VerticalAlignment.Equals(other.VerticalAlignment)
-                && this.Shadow.Equals(other.Shadow)
-                && this.FontSize.Equals(other.FontSize)
-                && this.FontColor.Equals(other.FontColor)
-                && this.FontName.Equals(other.FontName)
-                && this.FontFamilyNumbering.Equals(other.FontFamilyNumbering)
+                   bold == otherF.bold
+                && italic == otherF.italic
+                && underline == otherF.underline
+                && strikethrough == otherF.strikethrough
+                && verticalAlignment == otherF.verticalAlignment
+                && shadow == otherF.shadow
+                && fontSize == otherF.fontSize
+                && fontColor.Equals(otherF.fontColor)
+                && fontName == otherF.fontName
+                && fontFamilyNumbering == otherF.fontFamilyNumbering
                 ;
         }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLNumberFormat.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLNumberFormat.cs
index de38a6e..d474dc0 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLNumberFormat.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLNumberFormat.cs
@@ -83,9 +83,10 @@
 
         public bool Equals(IXLNumberFormat other)
         {
+            var otherNF = other as XLNumberFormat;
             return
-            this.NumberFormatId.Equals(other.NumberFormatId)
-            && this.Format.Equals(other.Format)
+            numberFormatId == otherNF.numberFormatId
+            && format == otherNF.format
             ;
         }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLProtection.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLProtection.cs
index a47da26..917c8aa 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLProtection.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLProtection.cs
@@ -62,8 +62,9 @@
 
         public bool Equals(IXLProtection other)
         {
-            return this.Locked.Equals(other.Locked)
-                   && this.Hidden.Equals(other.Hidden);
+            var otherP = other as XLProtection;
+            return locked == otherP.locked
+                   && hidden == otherP.hidden;
         }
 
         public override bool Equals(object obj)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLStyle.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLStyle.cs
index 46a4316..3cb5334 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLStyle.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLStyle.cs
@@ -78,12 +78,19 @@
         public bool Equals(IXLStyle other)
         {
             return
-            this.Font.Equals(other.Font)
-            && this.Fill.Equals(other.Fill)
-            && this.Border.Equals(other.Border)
-            && this.NumberFormat.Equals(other.NumberFormat)
-            && this.Alignment.Equals(other.Alignment)
-            && this.Protection.Equals(other.Protection)
+            //    this.Font.GetHashCode().Equals(other.Font.GetHashCode()) 
+            //&&  this.Fill.GetHashCode().Equals(other.Fill.GetHashCode())
+            //&& this.Border.GetHashCode().Equals(other.Border.GetHashCode())
+            //&& this.NumberFormat.GetHashCode().Equals(other.NumberFormat.GetHashCode())
+            //&& this.Alignment.GetHashCode().Equals(other.Alignment.GetHashCode())
+            //&& this.Protection.GetHashCode().Equals(other.Protection.GetHashCode()) 
+
+                this.Font.Equals(other.Font)
+            &&  this.Fill.Equals(other.Fill)
+            &&  this.Border.Equals(other.Border)
+            &&  this.NumberFormat.Equals(other.NumberFormat)
+            &&  this.Alignment.Equals(other.Alignment)
+            &&  this.Protection.Equals(other.Protection)
             ;
         }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLAddress.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLAddress.cs
index 1c6482a..f5e51c2 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLAddress.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLAddress.cs
@@ -23,6 +23,8 @@
             this.columnLetter = null;
             this.fixedColumn = fixedColumn;
             this.fixedRow = fixedRow;
+
+            hashCode = rowNumber ^ columnNumber;
         }
 
         /// <summary>
@@ -38,6 +40,7 @@
             this.columnLetter = columnLetter;
             this.fixedColumn = fixedColumn;
             this.fixedRow = fixedRow;
+            hashCode = rowNumber ^ ColumnNumber;
         }
 
 
@@ -82,6 +85,8 @@
             }
 
             columnNumber = 0;
+
+            hashCode =  rowNumber ^ ColumnNumber;
         }
         #endregion
 
@@ -393,14 +398,7 @@
 
         public static Boolean operator ==(XLAddress xlCellAddressLeft, XLAddress xlCellAddressRight)
         {
-            if (//xlCellAddressLeft.Worksheet == xlCellAddressRight.Worksheet && 
-                xlCellAddressLeft.rowNumber == xlCellAddressRight.rowNumber)
-                if (xlCellAddressRight.columnNumber > 0)
-                    return xlCellAddressLeft.ColumnNumber == xlCellAddressRight.columnNumber;
-                else
-                    return xlCellAddressLeft.ColumnLetter == xlCellAddressRight.columnLetter;
-            else
-                return false;
+            return xlCellAddressLeft.Equals(xlCellAddressRight);
         }
 
         public static Boolean operator !=(XLAddress xlCellAddressLeft, XLAddress xlCellAddressRight)
@@ -456,12 +454,10 @@
             return ((XLAddress)obj).GetHashCode();
         }
 
+        int hashCode;
         public override Int32 GetHashCode()
         {
-            return
-                Worksheet.GetHashCode()
-                ^ rowNumber 
-                ^ ColumnNumber;
+            return hashCode;
         }
 
         #endregion
@@ -471,6 +467,9 @@
         public Boolean Equals(IXLAddress other)
         {
             var right = other as XLAddress;
+            if (hashCode != right.hashCode)
+                return false;
+
             if (this.rowNumber == right.rowNumber)
                 if (right.columnNumber > 0)
                     return this.ColumnNumber == right.columnNumber;
@@ -482,7 +481,7 @@
 
         public override Boolean Equals(Object other)
         {
-            return this == (XLAddress)other;
+            return Equals((XLAddress)other);
         }
 
         #endregion
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
index ca492f9..b59cebd 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook.cs
@@ -25,7 +25,7 @@
             NamedRanges = new XLNamedRanges(this);
             CustomProperties = new XLCustomProperties(this);
             PopulateEnums();
-            Style = DefaultStyle;
+            Style = new XLStyle(null, DefaultStyle);
             RowHeight = DefaultRowHeight;
             ColumnWidth = DefaultColumnWidth;
             PageOptions = DefaultPageOptions;
@@ -258,67 +258,70 @@
         #endregion
 
         #region Static
-
+        private static IXLStyle defaultStyle;
         public static IXLStyle DefaultStyle
         {
             get
             {
-                var defaultStyle = new XLStyle(null, null)
+                if (defaultStyle == null)
                 {
-                    Font = new XLFont(null, null)
+                    defaultStyle = new XLStyle(null, null)
                     {
-                        Bold = false,
-                        Italic = false,
-                        Underline = XLFontUnderlineValues.None,
-                        Strikethrough = false,
-                        VerticalAlignment = XLFontVerticalTextAlignmentValues.Baseline,
-                        FontSize = 11,
-                        FontColor = XLColor.FromArgb(0, 0, 0),
-                        FontName = "Calibri",
-                        FontFamilyNumbering = XLFontFamilyNumberingValues.Swiss
-                    },
-
-                    Fill = new XLFill(null)
-                   {
-                       BackgroundColor = XLColor.FromIndex(64),
-                       PatternType = XLFillPatternValues.None,
-                       PatternColor = XLColor.FromIndex(64)
-                   },
-
-                    Border = new XLBorder(null, null)
+                        Font = new XLFont(null, null)
                         {
-                            BottomBorder = XLBorderStyleValues.None,
-                            DiagonalBorder = XLBorderStyleValues.None,
-                            DiagonalDown = false,
-                            DiagonalUp = false,
-                            LeftBorder = XLBorderStyleValues.None,
-                            RightBorder = XLBorderStyleValues.None,
-                            TopBorder = XLBorderStyleValues.None,
-                            BottomBorderColor = XLColor.Black,
-                            DiagonalBorderColor = XLColor.Black,
-                            LeftBorderColor = XLColor.Black,
-                            RightBorderColor = XLColor.Black,
-                            TopBorderColor = XLColor.Black
+                            Bold = false,
+                            Italic = false,
+                            Underline = XLFontUnderlineValues.None,
+                            Strikethrough = false,
+                            VerticalAlignment = XLFontVerticalTextAlignmentValues.Baseline,
+                            FontSize = 11,
+                            FontColor = XLColor.FromArgb(0, 0, 0),
+                            FontName = "Calibri",
+                            FontFamilyNumbering = XLFontFamilyNumberingValues.Swiss
                         },
-                    NumberFormat = new XLNumberFormat(null, null) { NumberFormatId = 0 },
-                    Alignment = new XLAlignment(null)
-                        {
-                            Horizontal = XLAlignmentHorizontalValues.General,
-                            Indent = 0,
-                            JustifyLastLine = false,
-                            ReadingOrder = XLAlignmentReadingOrderValues.ContextDependent,
-                            RelativeIndent = 0,
-                            ShrinkToFit = false,
-                            TextRotation = 0,
-                            Vertical = XLAlignmentVerticalValues.Bottom,
-                            WrapText = false
+
+                        Fill = new XLFill(null)
+                       {
+                           BackgroundColor = XLColor.FromIndex(64),
+                           PatternType = XLFillPatternValues.None,
+                           PatternColor = XLColor.FromIndex(64)
+                       },
+
+                        Border = new XLBorder(null, null)
+                            {
+                                BottomBorder = XLBorderStyleValues.None,
+                                DiagonalBorder = XLBorderStyleValues.None,
+                                DiagonalDown = false,
+                                DiagonalUp = false,
+                                LeftBorder = XLBorderStyleValues.None,
+                                RightBorder = XLBorderStyleValues.None,
+                                TopBorder = XLBorderStyleValues.None,
+                                BottomBorderColor = XLColor.Black,
+                                DiagonalBorderColor = XLColor.Black,
+                                LeftBorderColor = XLColor.Black,
+                                RightBorderColor = XLColor.Black,
+                                TopBorderColor = XLColor.Black
+                            },
+                        NumberFormat = new XLNumberFormat(null, null) { NumberFormatId = 0 },
+                        Alignment = new XLAlignment(null)
+                            {
+                                Horizontal = XLAlignmentHorizontalValues.General,
+                                Indent = 0,
+                                JustifyLastLine = false,
+                                ReadingOrder = XLAlignmentReadingOrderValues.ContextDependent,
+                                RelativeIndent = 0,
+                                ShrinkToFit = false,
+                                TextRotation = 0,
+                                Vertical = XLAlignmentVerticalValues.Bottom,
+                                WrapText = false
                             },
                         Protection = new XLProtection(null)
                             {
                                 Locked = true,
                                 Hidden = false
                             }
-                };
+                    };
+                }
                 return defaultStyle;
             }
         }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
index dfb11c4..d1cf344 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -809,7 +809,7 @@
                 var protection = (Protection)((CellFormat)((CellFormats)s.CellFormats).ElementAt(styleIndex)).Protection;
 
                 if (protection == null)
-                    xlStylized.InnerStyle.Protection = DefaultStyle.Protection;
+                    xlStylized.InnerStyle.Protection = new XLProtection(null, DefaultStyle.Protection);
                 else
                 {
                     xlStylized.InnerStyle.Protection.Hidden = protection.Hidden != null && protection.Hidden.HasValue && protection.Hidden.Value;
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
index 1be22e3..29cbd75 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -331,6 +331,7 @@
             using (package)
             {
                 CreateParts(package);
+                //package.Close();
             }
         }
 
@@ -345,6 +346,7 @@
             using (package)
             {
                 CreateParts(package);
+                //package.Close();
             }
         }
 
@@ -856,13 +858,15 @@
             Int32 stringId = 0;
             foreach (var s in modifiedStrings)
             {
-                    SharedStringItem sharedStringItem = new SharedStringItem();
-                    Text text = new Text();
-                    text.Text = s;
-                    sharedStringItem.Append(text);
-                    sharedStringTablePart.SharedStringTable.Append(sharedStringItem);
-                    sharedStringTablePart.SharedStringTable.Count += 1;
-                    sharedStringTablePart.SharedStringTable.UniqueCount += 1;
+                SharedStringItem sharedStringItem = new SharedStringItem();
+                Text text = new Text();
+                text.Text = s;
+                if (s.StartsWith(" ") || s.EndsWith(" "))
+                    text.Space = SpaceProcessingModeValues.Preserve;
+                sharedStringItem.Append(text);
+                sharedStringTablePart.SharedStringTable.Append(sharedStringItem);
+                sharedStringTablePart.SharedStringTable.Count += 1;
+                sharedStringTablePart.SharedStringTable.UniqueCount += 1;
 
                 sharedStrings.Add(s, (UInt32)stringId);
                 stringId++;
@@ -872,7 +876,7 @@
         #region GenerateWorkbookStylesPartContent
         private void GenerateWorkbookStylesPartContent(WorkbookStylesPart workbookStylesPart)
         {
-            var defaultStyle = DefaultStyle;
+            var defaultStyle = new XLStyle(null, DefaultStyle);
             Dictionary<IXLFont, FontInfo> sharedFonts = new Dictionary<IXLFont, FontInfo>();
             sharedFonts.Add(defaultStyle.Font, new FontInfo() { FontId = 0, Font = defaultStyle.Font });
 
@@ -1602,7 +1606,7 @@
 
             #region SheetProperties
             if (worksheetPart.Worksheet.SheetProperties == null)
-                worksheetPart.Worksheet.SheetProperties = new SheetProperties();// { CodeName = xlWorksheet.Name.RemoveSpecialCharacters() };
+                worksheetPart.Worksheet.SheetProperties = new SheetProperties();
 
             if (xlWorksheet.TabColor.HasValue)
                 worksheetPart.Worksheet.SheetProperties.TabColor = GetTabColor(xlWorksheet.TabColor);
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/UsingTables.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/UsingTables.cs
index b2c6693..bbdecf1 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/UsingTables.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/UsingTables.cs
@@ -27,7 +27,7 @@
             var table = range.CreateTable();    // You can also use range.AsTable() if you want to
                                                 // manipulate the range as a table but don't want 
                                                 // to create the table in the worksheet.
-
+            
             // Let's activate the Totals row and add the sum of Income
             table.ShowTotalsRow = true;
             table.Field("Income").TotalsRowFunction = XLTotalsRowFunction.Sum;
@@ -55,7 +55,6 @@
             headersTable.ShowTotalsRow = true;
             headersTable.Field(0).TotalsRowFormulaA1 = "CONCATENATE(\"Count: \", CountA(Headers[Table Headers]))";
 
-
             // Copy the names
             Int32 columnWithNames = columnWithHeaders + 2;
             currentRow = table.RangeAddress.FirstAddress.RowNumber; // reset the currentRow
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Styles/DefaultStyles.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Styles/DefaultStyles.cs
index c4cfb3b..5cc6858 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Styles/DefaultStyles.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Styles/DefaultStyles.cs
@@ -12,14 +12,6 @@
     {
         public void Create(String filePath)
         {
-            // The static default values are read-only so even if 
-            // you try to change a referenced type, the changes will be discarded.
-            var style = XLWorkbook.DefaultStyle;
-            style.Border.DiagonalUp = true;
-            style.Border.DiagonalDown = true;
-            style.Border.DiagonalBorder = XLBorderStyleValues.Thick;
-            style.Border.DiagonalBorderColor = XLColor.Red;
-
             // Create our workbook
             var workbook = new XLWorkbook();
 
diff --git a/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs b/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs
index 464f890..678a91a 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Sandbox/Program.cs
@@ -12,11 +12,11 @@
 {
     class Program
     {
-        static void Main(string[] args)
+        static void xMain(string[] args)
         {
             //var fileName = "DataValidation";
             //var fileName = "Sandbox";
-            var fileName = "Issue_6756";
+            var fileName = "Issue_0000";
             var wb = new XLWorkbook(String.Format(@"c:\Excel Files\ForTesting\{0}.xlsx", fileName));
             //var wb = new XLWorkbook();
             //var ws = wb.Worksheets.Add("Sheet1");
@@ -35,8 +35,7 @@
             //Now, when i use workbook.Worksheet("CCR").Range("B1:C34").RangeUsed().
             //The expect is B1:C29.
 
-            var ws = wb.Worksheet(1);
-            ws.CopyTo("012345678901234567890123456789");
+            
             wb.SaveAs(String.Format(@"c:\Excel Files\ForTesting\{0}_Saved.xlsx", fileName));
             //Console.ReadKey();
         }
@@ -52,7 +51,7 @@
             }
         }
 
-        static void xMain(string[] args)
+        static void Main(string[] args)
         {
             FillStyles();
             List<Double> runningSave = new List<Double>();
@@ -66,11 +65,11 @@
                 foreach (var i in Enumerable.Range(1, 1))
                 {
                     var ws = wb.Worksheets.Add("Sheet" + i);
-                    foreach (var ro in Enumerable.Range(1, 2000))
+                    foreach (var ro in Enumerable.Range(1, 10000))
                     {
-                        foreach (var co in Enumerable.Range(1, 100))
+                        foreach (var co in Enumerable.Range(1, 20))
                         {
-                            ws.Cell(ro, co).Style = GetRandomStyle();
+                            //ws.Cell(ro, co).Style = GetRandomStyle();
                             //if (rnd.Next(1, 5) == 1)
                                 //ws.Cell(ro, co).FormulaA1 = ws.Cell(ro + 1, co + 1).Address.ToString() + " & \"-Copy\"";
                             //else