public enum EnhancedInterfaceRenderer.ButtonStyles : System.Enum 

FarPoint.Win.Spread.EnhancedInterfaceRenderer ei = new FarPoint.Win.Spread.EnhancedInterfaceRenderer();
ei.ArrowColorDisabled = Color.Beige;
ei.ArrowColorEnabled = Color.DarkGoldenrod;
ei.ForeColor = Color.Tan;
ei.RangeGroupBackgroundColor = Color.Gold;
ei.RangeGroupButtonBorderColor = Color.Firebrick;
ei.RangeGroupLineColor = Color.BlanchedAlmond;
ei.ScrollBoxBackgroundColor = Color.Gold;
ei.SheetTabBorderColor = Color.Gold;
ei.SheetTabLowerActiveColor = Color.Gold;
ei.SheetTabLowerNormalColor = Color.Firebrick;
ei.SheetTabUpperActiveColor = Color.BurlyWood;
ei.SheetTabUpperNormalColor = Color.BlanchedAlmond;
ei.SplitBarBackgroundColor = Color.Bisque;
ei.SplitBarDarkColor = Color.Brown;
ei.SplitBarLightColor = Color.LightGoldenrodYellow;
ei.SplitBoxBackgroundColor = Color.Brown;
ei.SplitBoxBorderColor = Color.Red;
ei.SheetTabBorderColor = Color.Gold;
ei.SheetTabLowerActiveColor = Color.White;
ei.SheetTabLowerNormalColor = Color.Wheat;
ei.TabStripBackgroundColor = Color.Beige;
ei.TabStripButtonFlatStyle = FlatStyle.Popup;
ei.TabStripButtonLowerActiveColor = Color.Gold;
ei.TabStripButtonLowerNormalColor = Color.White;
ei.TabStripButtonLowerPressedColor = Color.AntiqueWhite;
ei.TabStripButtonStyle = FarPoint.Win.Spread.EnhancedInterfaceRenderer.ButtonStyles.Enhanced;
ei.TabStripButtonUpperActiveColor = Color.Gold;
ei.TabStripButtonUpperNormalColor = Color.Cyan;
ei.TabStripButtonUpperPressedColor = Color.Wheat;
ei.TabShape = FarPoint.Win.Spread.EnhancedInterfaceRenderer.SheetTabShape.RoundedRectangle;
fpSpread1.InterfaceRenderer = ei;