i haven't noticed a preference of color/sex for my BP's that take f/t. and for the ones that take live feeders - definitely no preference. they eat them all. it's funny when i go buy food for my snakes, they ask what color and sex. my local shop knows me, but when i stop by Petco sometimes - they're kinda shocked when i tell them it doesn't mater.

but i know BP's are picky. thank goodness mine are only picky about f//t vs. live.

anyway nice experiment. Walter seems to favor rats with color. u should also track the sex of the rats if u wanna go a step further. keep us updated on your findings.