Perhaps if you arrange the blocks differently, in a pattern of color, that might make it more to your liking.
Start with the greens in the diagonal, then migrate to the blues, then to the purples and finally the pinks. Just glancing the blocks you have, I think that is doable, even if you have to make a few more blocks of a few colors to balance it out.
Also play with the orientation of the blocks. You might like it better if they are oriented the same way.