Maybe you take a gander at Alex Anderson's book Neutral Essentials, check to see if your library or a friend has it.
https://www.amazon.com/Neutral-Essen.../dp/1571204180
My own personal epiphany that I got from Alex is to have white in there somewhere, it makes the quilt sparkle.
I'm sure there are other books out there, maybe even blogs that talk about how to "neutral".