Setting Palettes on Non-Primary Surfaces
In DirectX 2, palettes can be attached to any palettized surface (primary, back buffer, off-screen plain, or texture map). Only those palettes attached to primary surfaces will have any effect on the system palette. It is important to note that DirectDraw blits never perform color conversion—any palettes attached to the source or destination surface of a blit are ignored. Furthermore, the DirectDraw surface method, IDirectDrawSurface::GetDC, also ignores any DirectDrawPalette selected into the surface.
Non-primary surface palettes are intended for use by applications or Direct3D, or other 3D renderers.