Lately I've been having this glitch, you can see the glitch in the first picture. The sim is all white texture except her face. In the second picture is how she is supposed to look. I can "fix" it by going though Nraas Master Controller and Edit sim. When I go into CAS she looks fine, then I edit the color of the clothing piece a bit and press OK, then she started looking like in the second picture, the way she is supposed to look.
This does not only happen with her, I have been having other sims having the same issue, but then instead of being all white, they will be fully colored in whatever texture they are wearing at that moment.
In the pictures she is wearing CC but I have had this happen to sims who were only dressed in EA underwear too, sims were male.
Sometimes when that happens my game crashes, sometimes when I start the game up they are already like that and I have to do that Master Controller edit trick to get them to look normal, usually it only happens to a sim once and the next time it's another sim who is affected.
Also it's have been happening to all kind of clothes categories like formal, casual, sleepwear, athletic.





Also to note I'm playing on a strong PC of only 1,5 years old. GTX 970 i7 ssd.

All white Sim skin does sound like a texture glitch -- like nitromon said, the fact that it only happens to the Sim body makes me think it's due to bad skin textures. If it were due to clothes ambient being messed up, the entire Sim minus the head would be one color. It looks like it's affecting textures even without Sims wearing the clothes/skins it's attached to. Amusingly enough, I remember the first 3D penis meshes grabbing the textures from whatever shoes the Sim was wearing.

Remove your custom skins, delete your cache files and reload.

Edit: could also happen from accessories, I remember someone posting a thread and identifying a bracelet or ring as the culprit.

For people who might have it too:
It got solved after I put high detail lot to 1 instead of 4, in the end your graphic card etc. don't matter if Sims 3 can only use like 3,4 - 4 gb max.
It has nothing to do with bad CC.