I worked on this short film back in March for a SFU student. They wanted me to do this leper arm, or something gross. So this is what I came up with. It was done with out of kit effects gelatin then colored with Illustrator palette. I think It turned out great for doing it with no direction! Very gross looking!
In the right picture you'll notice it has a shine to it or a sheen effect. This was done by adding some glycerin over the colored gelatin. Note, you will not want to do this yourself, the glycerin will start to break down the gelatin. I did it cause I had some to use up and also cause I knew this effect wasn't going to be on the girls arm for long. You can get the same effect with Vaseline, and it will not effect the gelatin!