She prefers the blue ones, she said it herself. I don't think I like girls that have a favourite color of m&m's. How could one possible prefer one color above another? They all taste the same, don't they? The color is caused by color additives, and those additives don't change the flavour. But more important, it is pure discrimination to the other colors. Every m&m has the right to be eaten equally, with just as much enjoyment as his little brothers, there should be a law for that. Maybe she is one of those few people (mainly French-speaking girls like herself) who can taste the minimal taste difference between a blue and a red m&m, but of course it is much more likely that the preference is decided psychically.