Don't you think it's biased to choose favorite colors?
biased past participle, past tense of bi·as (Verb)
Show prejudice for or against (someone or something) unfairly: "the tests were biased against women"; "a biased view of the world".
Influence unfairly to invoke favoritism: "her story failed to bias the jury".
We are showing favoritism towards a color that cannot control what it looks like.