Description from extension meta
Applies a random skintone to any skintone-eligible emoji that doesn't already have one.
Image from store
Description from store
The default yellow (or non-human) skin tones are a great feature of the emoji spec. A vast improvement over default white for sure, but it isn't realistic. It simply avoids the racial diversity issue.
If you would like to bring race back to your emoji in an impartial way, install this extension.