I'm going to borrow weste's picture as a guideline.
http://www.quiltingboard.com/t-9438-1.htm
If I were you, I would find the fabric from the large center square. It is generally a multicolor print. From there, you will have some options that should have some contrast. One color from the square will be the center row of little squares. The other will be a lighter color value and when you have that, select some tone on tones that graduate the color.
In my LQS, the ladies are incredibly helpful to lend a helping hand. They make suggestions without being pushy and overbearing.
Do you have any idea which colors you want to use?