Sims modder Simsperience was a little bummed that her skin sliders from The Sims 3 were missing in the newest installment. Hoping to make her residents a little more colorful — literally — she has added a whopping 95 skin overlays for adults and children in The Sims 4 (babies can't have their skin color changed).
The way overlays work is that they replace the full face freckles slot option. You can then pair each of the 95 overlays with any of the 18 skin tones, resulting in 1710 possible combinations. You can still add freckles to your colorful Sim adults by selecting freckles from the lip mole detail slot, although this means you can't have both a lip mole and freckles while an overlay is in effect. Sadly, when it comes to kids, you will have to choose between overlays or freckles.
Download the mod package at the bottom of Simsperience's page here.