OK CeCe, I think I know what's wrong.
Shut down your game and check your Mods folder. Take out the Non Default skin mod by Rez Delnava (there should only be one, but if there are more, take out all).
This version of the mod by Rez Delnava doesn't work with the latest patch AND Late Night. We have to wait for a newer version of the mod.
You can start up the game again and the new sliders should be there !! :D
In the CAS start up screen, you can choose only 6 skin tones. However I think all non default skin tones you have, will still work in Late Night. But you can only select / view 6 in the CAS start up screen....
If you want to use another skin tone (work around), go to your Sim bin and look up a Sim of yours with the skin tone you want. Reset his looks in CAS and start working on creating a new Sim.
I hope this helps !! ;)