The folks over atSims 4 Stuff n Thingshave released a brand new create-a-sim recolor tool. To use the tool you will also need to useS4PE, then you can jump in a get your hands dirty with recolors! Let the modding begin!
Download CAS Recolor Tool–Instructions Forum
*Update* – Our reader JD has created and shared some custom icons for the recolor tool. Feel free to download!