Specifies the number of color indexes in the color table that are actually used by the bitmap. If this value is zero, the bitmap uses the maximum number of colors corresponding to the value of the biBitCount member for the compression mode specified by biCompression. If biClrUsed is nonzero and the biBitCount member is less than 16, the biClrUsed member specifies the actual number of colors the graphics engine or device driver accesses. If biBitCount is 16 or greater, the biClrUsed member specifies the size of the color table used to optimize performance of the system color palettes. If biBitCount equals 16 or 32, the optimal color palette starts immediately following the three DWORD masks. If the bitmap is a packed bitmap (a bitmap in which the bitmap array immediately follows the BITMAPINFO header and is referenced by a single pointer), the biClrUsed member must be either zero or the actual size of the color table.
Public biClrUsed As Integer