As illustrated in the picture above, there was an error with my fantasy skintone fixes - blue, green, red, etc - which meant dark patches appeared on the underside of the penis. This update corrects that issue for all of the affected tones.
If you're not familiar with my skintone fixes, they override the game's skintones so you see skin color on your sim's penises (otherwise you would see odd black textureless spaces). If you don't use my skintone fix, or a fix from another creator, it's likely the genitals won't look correct on your sim.
The skintone fixes work for SimpleGens and RealGens, and likely work for any other body parts that are similarly textured mapped (it will probably work for WW and Noir penises, for example).
There are three files in the zip - Base Game, Get to Work, and Island Living. Install the files for the packs you own and want to fix.