> For example if you ask a bilingual human what their favorite color is, the answer will be that color regardless of what language they used to answer that question.

It's a very interesting question. Has someone measured it? Bonus point for using a conceal way so the subjects don't realize you care about colors.

Anyway, I don't expect something interesting with colors, but it may be interesting with food (I guess, in particular desserts).

Imagine you live in England and one of your parents is form France and you go there every year to meet your grandparents, and your other parent is from Germany and you go there every year to meet your grandparents. What is your favorite dessert? I guess when you are speaking in one language you are more connected to the memories of the holidays there and the grandparents and you may choose differently.