Maybe the Unicode consortium made a mistake by specifying them as bright yellow, which people now associate strongly with the Simpsons, where white people are represented as bright saturated yellow.
Those who aren't as familiar with the Simpsons would probably associate yellow with Asian --- which sort of makes sense due to them originally being Japanese.
Coloured emoji don't make much sense to me either --- they are text like any other, and should thus be represented with the same colour as the text.