Really vibrant colors like that are really hard to make yourself because as you add more and more color you dry out the fondant. I would buy premade fondant instead like Satin Ice for colors like these.
I've made the yellow green- i used grass green and added lemon yellow with great results! The fuchsia- i did that too, i used fuchsia (americolor) and it was spot on! I would recommend trying a small batch of each first
for purple- i highly recommend using red or pink (or both) plus blue, to minimize fading... again small batches until you get the shade you need!
Thanks alot for your time and help. I so appreciate.
You to Catlharper for your help and time as well...
Americolor Electric Purple, Americolor Electric Green, Americolor Regal Purple
americolor has fushia, I bought some a couple of week ago