To be honest the gems all started really dark green and I did layer up to a more bright green (on the upmost parts more white-green then anything else). But I felt the dark green contrasted to much with the ship and jumped out way too much for my taste. So I made it less darker on purpose.
If you look at the right destroyer in the top picture, you'll notice that their are flamey kind of purple lines on the yellow fore section. (my wifes idea which I tried, but I was not impressed by my own skill to do them properly) On the GC picture they are better seen:

And the inspiration:

(the flower grows red poisenous berries, these start out green, so I made the guns red: aka poison)
The Hellebore and Aconite will be similar interesting to be inspired by the flower but the Hemlock will be very hard to do.