They work for child-elder and they are all compatible with each other, and show up in correct order in CAS, so it wouldn't matter if you downloaded one package, or all of them.
But if you have GTW, you'll get 26 new skintones for aliens as well! And as said in the title, these are Maxis match, so they look exactly the same as the Maxis skintones, only in many more colors. I say that it does not require GTW because the two fantasy packs are in ONE package, meaning that the same package works for both humans and aliens. There are 14 warm and cool skintones, 16 fantasy skintones, and 10 pastel fantasy skintones. Thanks to CmarNYC's Skininator tool, I bring you 54 new skintones! Sure, she made this so everyone could make custom skintones, but I would imagine not everyone knows how to use it, so I made some new skins for the non-creators on MTS. Hey there, community! Sorry that I haven't posted in awhile, but I finally made a new project, and it's a big one to say the least. Since the skin tones update, THIS MOD NO LONGER WORKS! But don't worry, more updated content will be coming soon!