In your opinion, how would YOU unite these colours? By that I mean which colours/shades would you use to blend them all into a palette of complimentary of hues? This is not an exercise with a hidden agenda to purchase more plants that would, in turn, lead to purchasing even more plants to unite the many hues already owned. It's not. Really. No, it isn't...
and this bunch of awful shades...
I understand your patience in this but there is only one more pic to suffer...I promise...
Of course if there are any colours that would be hideous, in your opinion, please do not hesitate to mention them in case I commit the ultimate faux pas in the collection of a rainbow....
...I know I don't have much to work with, however, your input may be crucial in my rehabilitation.