All colors are passed as 32-bit signed values. These are either indexes into the Logical Color table, logical palette indexes, or representations of 24-bit Red-Green-Blue (RGB) values. Some special attribute values can be passed to the graphics engine and returned by GreGetAttributes:

CLR_FALSE

All color planes or bits, or both, are 0.

All color planes or bits, or both, are 1.

This index is never loaded explicitly. It always produces White when the default color table is in force or when the index is set to RGB. With a realized color table and an index that is not RGB, the value CLR_WHITE produces the background color CLR_BACKGROUND.

This index is never loaded explicitly. It always produces Black when the default color table is in force or when the index is set to RGB. With a realized color table and an index that is not RGB, CLR_BLACK produces the neutral color CLR_NEUTRAL. See Color Functions.

CLR_FALSE and CLR_TRUE provide useful operands for BitBlt logical operations. CLR_DEFAULT is the default value at the API. It is a reserved value and is not passed to the presentation driver.