The Adam And Eve Challenge

Exactly what @RaeNic said, and with the A&E challenge, we are populating the town so if I start with neutral sims (white in my case) and change the future heirs to suit my color choice, then I will have a rainbow populated world. I think in the original Rainbowcy, Berrypie27 made a world that was populated with rainbow sims and began her legacy there...even her houses reflect the colors of the rainbow, and their names etc. I am just changing the sims colors however instead of populating my town beforehand since in this challenge there are no Sims around except NPS.