Eliminate the 3 non-blue blocks and see if that helps it visually for you. Use those colors in narrow borders and/or binding. Or......
Try turning the plain blocks over and using the reverse side of the fabric....you paid for both sides, why not use them? Or......
Change out the plain (but printed) blocks with a white or other pale solid color. Or.....
Leave it as is and realize that "busy" for you likely won't be for a child!
Jan in VA