Re: Lighter skin tones not showing up after update

@FormalFudge  Please clear Origin's cache and then repair the game: open your Origin game library, right-click on the Sims 4 icon, and select Repair.

https://help.ea.com/en-us/help/faq/clear-cache-to-fix-problems-with-your-games/

If that doesn't help, please move your entire Sims 4 folder out of Documents\Electronic Arts and onto your desktop.  When you launch the game, a clean folder will spawn with no content.  Don't add anything to this folder yet; just see whether the problem shows up in a new save.

If CAS looks normal now, you can copy your saves and other content to the new Sims 4 folder.  It's best to copy the content in batches though, testing each time to see whether the issue returns.  If and when it does, you'll know that the problem was one of the files you just moved, and you can split that last batch and retest until you've found the culprit.