I'm working on an isometric game engine, based on the Dink Smallwood engine. I'm using DirectX 7 to do the usual stuff, but I'm having trouble with transparencies.

I want to have white as a transparent colour for a sprite, and I have set its transparent colour correctly, but it won't work at all. However, black works, and all other sprites from other sources display correctly.

My theory is that the bitmap uses a different palette than others, and the engine can't work out which is white. Is there any way to get the engine to find out?

Thanks,
DesPlesda