Sewcrafty-
One thing that helped me overcome this stopping block is I asked myself some questions:
Why do I feel this way? Who says it has to be all color coordinated? Who cares? Are the Quilt Police gonna come and drag me off to who knows where? What's it gonna hurt? and Why does it matter?
If I don't like the quilt after it is made, I can donate it.
My biggest naysayer is my DD. My biggest supporter is my DS.
DD needs the control in colors. DS has taken art school and taught me to look at other color combinations. That was the most freeing experience. Think outside the box. It is very satisfying and freeing.