Here's a collection of figures with a variety of green flesh colors. Three of them were part of the kickstarter videos.
The two Reaper Trolls were used for the Painting Green Flesh Tones video. The Raging Heroes Ork Warboss was used for the Shaded Basecoat video.
As you look at these, you will notice that the color varies here ans there. Some greens are warmer, some are cooler. Also, some of the greens are very muted, or "grayed down". That can be done by mixing in some red or brown.
Other colors are more pure, or 'saturated' This is discussed a lot, especially in the Green With Envy color theory video concerning greens.
It does not really matter what the size of the figure is, or what type it is... making more variations in those green flesh colors can make anything seem more elaborate or interesting.
I try to have transitions in the color across a single figure. The trolls are a very good example of that. You get the whole range of warmer and cooler greens, as well as the more muted colors on the back.
Mixing in purple of one shade or another with the green also yields some interesting results! That is a favorite trick of mine.
This is just a drop in the proverbial bucket when it comes to greens and skin tones made with them. Hopefully this gives you a few ideas!