I have heard stories of snakes that are picky about the color or even the sex of the rodents that they will eat. I even read once about someone who had a snake that would only eat after the prey item had been thawed, refrozen, and thawed a second time. The theory was that it smelled different because of the breakdown of tissues caused by the freezing/thawing processes.

None of my snakes have been so picky. I raise mice in a whole rainbow of colors, and I haven't noticed any color preferences in any of my snakes.

My theory is that even if a snake did become imprinted on a certain color of mouse, it would be pretty easy to convert the snake with a little tough love. I would think this sort of pickiness would be much easier to overcome than a snake who only wanted live, or who wanted mice but not rats, etc.