Individually I love the color, as a unit they may blend together and become blah.
Possibly could change the color of the webbing, maybe a orange or blue on like 2 or 3, to individualize them and break the unit up a bit.
I wouldn't do more than the purple-ish webbing and then one other color, whatever you choose.
With all the green (skin, base, scales) things may be "muddy" looking if all the Trolls are all similar.
I could be WAY off base too, still working on my color theory, but hey just throwing it out there.