I have this issue, too. it's extremely inconvenient, because the sims also don't autonomously try to fill their needs with this bug. It's made the game extremely difficult to play.
I have the same issue after the latest game update for the growing together expansion pack. Never came across this bug until after I downloaded the new pack and the update that came with it. I though it was mod related too so took all that out. Even changed my main sims 4 folder name and stated a new sims 4 game to see if it will give me the same bug and it resolved the issue for a while and then an error occurred and same bug happened again. The needs bar not changing color to depict the actual portrayal of the sims needs. As mentioned in other treads here, moving to a different lot fixes the issue but after spending time at a different lot the same thing happens again until sim goes to another lot/ goes home. This makes playing the game very annoying and not fun.
I have the same problem but only with the one household I'm playing, it seemed to start once my sim had discovered the active trait. The problem is fixed momently if I go to CAS or travel. I don't have any mods.
