If that doesn't work to get the hair to display properly, another thing it could be is that it is old and predates the additional color swatches that were added a while ago. You might have something similar going on and if that is the case, you're going to have to go through you CC to find the troublemaker. Once I found and removed it, the sims were back to normal. It took me a while to figure out it was a tattoo doing that. A while back, I had a CC tattoo, that after one of the updates, still looked great in CAS but in live mode it turned the sims it was on completely black.
CC 3D eyelashes, earrings, tattoos, piercings would be the first things I would check as possible causes. If it does, it has to be something else in your mods folder interfering with it. Put the hair on a sim and go to live mode to see if shows up. Then put the hair that is causing the problem in the new game's mod folder by itself and restart the game. The easy way to check is to rename your current The Sims 4 folder and start the game to let it generate a new one. Most likely, it might be something else in your mods folder could be interfering with it in live mode. What can I say, it was late, I was tired, and I just missed it.