Before I always did the kids last and left cas because Id just go down the line and kids are at the end. I can’t take credit for this I stumbled upon this when I started researching berry Sims after searching for solutions off and on for years. I usually go through from winter to everyday, fix the hair colors and the click on an adult sim before leaving Cas and their hair should stay. When you go into cas and make the kids after changing everything else the last thing you do is fix all of the hair colors. But just in case I have found this solution super helpful and since I’ve had almost no problems with this anymore. Maybe you guys already know this and I was just dumb or something. I looked for a solution forever and never found anything. So I don’t know if anyone else has this problem with cc hair where the kids and toddlers hair will constantly randomly change color.