Old Method (You have to iterate through every item):
ws2.Columns("G:H").ForEach(c => c.Style.Fill.BackgroundColor = Color.Blue);

New Method (No iteration necessary, the program knows you want to apply the style/whatever to the entire collection):
ws2.Columns("G:H").Style.Fill.BackgroundColor = Color.Blue;

Right now it only works with columns but I'll add it to rows and ranges before release.