You can determine the colour depth by using the GraphicsDepth() function. In windowed mode, it should return the colour depth of the desktop.
My graphics card doesn't do 8-bit so I can't test it (its possible that GraphicsDepth() will never return a value lower than 16), but in theory you can check to see if GraphicsDepth() returns 8, and if so, go to fullscreen.
Might be worth a go, anyway...
My graphics card doesn't do 8-bit so I can't test it (its possible that GraphicsDepth() will never return a value lower than 16), but in theory you can check to see if GraphicsDepth() returns 8, and if so, go to fullscreen.
Might be worth a go, anyway...