Originally Posted by
PatriceJ
my own inclination would be to use something lightish in [light] areas; darkish in [dark areas]; and red for the background..
I really like Patrice's idea of using different color threads for different areas - that will keep the quilting subtle and keep the focus on the pieced fabrics.
For bargello quilts, I think it can be very attractive to quilt straight or gently curved lines through the center of the curves created by the pieced fabrics. You can then continue to echo those curves through some or all of the red background fabric. Here's a drawing of some of the lines:
Please note that I drew my lines with high contrast colors to make viewing them in the photo easier; I think making color choices that blend into the fabrics will be very attractive and keep the focus on the pieced fabrics.