I forgot to mention this in my previous mail, but if we're going to change the color fixup code, we should really integrate it properly into the backend. Ie, shader_glsl_get_sample_function() and the ARB equivalent should be aware of the format conversion, in order to prevent having to swizzle from components that aren't available, like can happen with WINED3DFMT_L6V5U5.
Agreed. Although I think there was a reason why we did not do that when we implemented the current structure of the color conversion code to replace a hacky ARB integration of the color conversion.