It depends slightly on the background. No matter what color you superimpose pink on, you won't see it as green, but the shading may change slightly. So the color is still independent of the brain, bar some small corrections made by our visual processing software and hardware.

Also note that bleaching of pigments etc doesn't mean that color resides in the mind. That's like putting a magnet on my download cable, corrupting the data stream, and then claiming that the data doesn't exist independent of my computer (or resided there).