Wow, that's awful your game is doing that! I don't think I have that problem. It might be related to a particular video card? I recall Intel chips and cards have always had some weird effects on this game from long ago. Maybe that is still the problem or a driver problem for a video card.
What is the brand of your video card and have you updated the driver lately, or better yet, rolled back the driver version if this just started happening? It's really obvious and I would guess a video card problem since you don't have any cc on these Sims at all.
ETA: The only time I saw anything like this in my game is when kids (girls) would wear that puffy sleeve top, a moder had to fix that mesh it was a mesh problem by Maxis. But never like this on so many outfits.
ETA: The only thing remotely known about this from way back is using the shader cheats if you don't have any custom skins in game at all.
http://modthesims.info/t/202297
Or have you tried to make any outfits and have unfinished projects in game for recolors etc.?