I agree with HotButton’s comment about it being more art than design. Although it could be used as part of a larger design piece.
That said, I think you did a good job with this. The color palette is nice, and the overall layout and balance is pleasing. My only suggestion would be to look at a couple of different options for the top right box. I don’t mind the diagonal color split; but, with the circle being on the smaller side, it really emphasizes the diagonal which seems a little out of place with the others.