DWORD SetBkColor( DWORD crColor );
crColor
Specifies the new background color.
Sets the current background color to the specified color. If the background mode is OPAQUE, the system uses the background color to fill the gaps in styled lines, the gaps between hatched lines in brushes, and the background in character cells. The system also uses the background color when converting bitmaps between color and monochrome device contexts.
If the device cannot represent the specified color, the system sets the background color to the nearest physical color.
The previous background color as an RGB color value. If an error occurs, the return value is 0x80000000.
CDC::GetBkColor, CDC::GetBkMode, CDC::SetBkMode, ::SetBkColor