By not having a colour wheel for certain objects or parts it makes player ask for more swatches that take up time and then because there isn’t enough swatches are not the colour they want (especially when they don’t have a basic white and black). It makes it harder to match things together. I think there is justification to put a colour wheel system in certain place as we already have ones for cats and dogs and it would make player not as frustrated with the game.
Where should a colour wheel be used
Skin: I think the skin tones in the sims 4 need a complete overhaul again the texture the darker skins are not right for some and do not look realistic. All skin tones need undertones of cool. neutral, warm slider that comes along with a skin tone colour wheel.
Hairs: I think this will allow player to create own ombres to their taste with colour they want, and pattern stamps they want so we do not have a limited option with the basic few hair colour we have. (this in facial hair, eyebrows and body hair if we get it)
Eyes: create own heterochromia eyes and patterns
Tattoo: I think we should be to create own body tattoo and draw own our sims so our sim don’t look repetitive and tattoos can match up properly together you could also stamp tattoo design in anyplace you want. ( check: https://forums.thesims.com/en_US/discussion/948097/what-would-you-like-in-a-fame-game-pack#latest
Frames: bedframes, window frames, doorframes, furniture frames, picture frames. By having using a colour wheel to change the frames of objects will make it easier to match items together.