If you have enough fabric, play around with it and try switching the background fab to the bright green and put the background fabric around the white block and see what that does. At least lay the purples and fairy pieces on a piece of the bright green to save from cutting it and see what you think then.
I love this block and the way it is, but who knows what a color change can always do for one. What is the name of this block if I might ask? Is this from a special pattern?
That is going to be a BEAUTIFUL quilt when it is finished whatever color you go with.