typedef struct _DDCOLORKEY{
DWORD dwColorSpaceLowValue;
DWORD dwColorSpaceHighValue;
} DDCOLORKEY,FAR* LPDDCOLORKEY;
Describes a source or destination color key or color space. A color key is specified if the low and high range values are the same.
Low value, inclusive, of the color range that is to be used as the color key.
High value, inclusive, of the color range that is to be used as the color key.