Whatsapp reactions to messages for android will finally let you change the skin tones of reactions.
As you can see currently it will only support thumbs up and folded hands emojis only; you can change the skin tone by changing the emoji colour within the emojis menu.
This may also indicate that Whatsapp reactions update is polishing up the reaction features much more. As you may be aware WhatsApp also rolled out detailed reactions as well. This feature is currently in testing.