diff --git a/ClosedXML/Excel/Style/XLFill.cs b/ClosedXML/Excel/Style/XLFill.cs
index d5d6849..3dc4fdc 100644
--- a/ClosedXML/Excel/Style/XLFill.cs
+++ b/ClosedXML/Excel/Style/XLFill.cs
@@ -125,7 +125,20 @@
             get { return Key.PatternType; }
             set
             {
-                Modify(k => { k.PatternType = value; return k; });
+                if (PatternType == XLFillPatternValues.None &&
+                    value != XLFillPatternValues.None)
+                {
+                    // If fill was empty and the pattern changes to non-empty we have to specify a background color too.
+                    // Otherwise the fill will be considered empty and pattern won't update (the cached empty fill will be used).
+                    Modify(k =>
+                    {
+                        k.BackgroundColor = XLColor.FromTheme(XLThemeColor.Text1).Key;
+                        k.PatternType = value;
+                        return k;
+                    });
+                }
+                else
+                    Modify(k => { k.PatternType = value; return k; });
             }
         }
 
diff --git a/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/Excel/XLWorkbook_Save.cs
index 74edc65..57e3f00 100644
--- a/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -3982,7 +3982,7 @@
                                 break;
                         }
 
-                        if (backgroundColor.HasChildren)
+                        if (backgroundColor.HasAttributes)
                             patternFill.AppendChild(backgroundColor);
                     }
                     else
@@ -4012,7 +4012,7 @@
                                 break;
                         }
 
-                        if (foregroundColor.HasChildren)
+                        if (foregroundColor.HasAttributes)
                             patternFill.AppendChild(foregroundColor);
                     }
                     break;
@@ -4039,7 +4039,7 @@
                             break;
                     }
 
-                    if (foregroundColor.HasChildren)
+                    if (foregroundColor.HasAttributes)
                         patternFill.AppendChild(foregroundColor);
 
                     backgroundColor = new BackgroundColor();
@@ -4062,7 +4062,7 @@
                             break;
                     }
 
-                    if (backgroundColor.HasChildren)
+                    if (backgroundColor.HasAttributes)
                         patternFill.AppendChild(backgroundColor);
 
                     break;
@@ -4071,10 +4071,7 @@
             if (patternFill.HasChildren)
                 fill.AppendChild(patternFill);
 
-            if (fill.HasChildren)
-                return fill;
-            else
-                return null;
+            return fill;
         }
 
         private bool FillsAreEqual(Fill f, XLFillValue xlFill, Boolean fromDifferentialFormat)