Once you have it figured out, they will be ten minutes or less!
I like the colours, and yes they go well together. Maybe your disappointment is in the placement? Move the white background print to the centre diamond and I think you'll get the contrast you are wanting!
Love the pattern ... and how you can vary the sizes of the inner diamond, smaller/larger to your desire. Also, if you want more ... you can add a diamond again, as you join your blocks together! Neat, eh?