BCGSuite for MFC
BOOL CBCGPDrawManager::GrayRect ( CRect  rect,
int  nPercentage = -1,
COLORREF  clrTransparent = (COLORREF)-1,
COLORREF  clrDisabled = (COLORREF)-1 

Fills a rectangle by the gray color with a specified percentage.

Nonzero if success; otherwise 0.

Use this function to fill a rectangle using the gray color with the specified by nPercentage percentage.

rectSpecifies the rectangle to be filled.
nPercentageThe gray color's percentage. Use this value to get various shades. 100 - lighter, -1 - default light.
clrTransparentTransparent color.
clrDisabledUse this color for de-saturation.