I love your color choices! Very nice!
Here are a few ideas I found:
http://quiltinspiration.blogspot.com...1_archive.html scroll down to THURSDAY, DECEMBER 20, 2012 - Peace on Earth
http://www.nydailynews.com/life-styl....950858?pgno=1 – you could do each child in a different tie-dye shirt!
http://nonniequiltingdreams.wordpres...ng-with-color/ - balance of color
http://nonniequiltingdreams.wordpres...ythm-homework/
http://mariaacevedo.com/sketches/sun-and-moon/ - would make a nice compliment to your Yin-Yang
I agree with Nanny -- show us your blocks as you go! Good Luck!