I am caucasian, get sun burnt easily… I left the emojis (faces) its Simpson color (are there other?) but hands… I cannot stand the cirrhotic yellow hands/arms, and need to switch their color at first occasion… I also tend to select black hair people though I am slightly brown… and many caucasian friends of mine use black hands… so I would say that in my environment your hypothesis is rather a background underfluctuation than a potential valid one…