Maybe approaching it in a different way might help. I am not color blind, but I have myopic macular degeneration, and I don't see straight lines like other folks do. (What looks straight to you looks curved to me.) I still enjoy quilting, and the lines look fine to me when I am done.
What if you select a fabric that has lots of colors in it as a "map" for a quilt. Surely those colors go together if they are already in one fabric. Then select other fabrics that go with the colors in that fabric. If you see the two colors as the same, they are, right? And if they matched in the original fabric, they should go together, right? Is that making any sense?
Other than that, I'd just tell folks I was color bind and the quilt looks fine to me...or I'd ask the person who questioned your colors to help you select the fabric for your next quilt, either at a store or from your stash. Couldn't take too long for someone to help you select fabrics that go together? And they could do it right then....?
Don't let this ruin your quilting enjoyment. I suspect that we don't all see colors the same anyway, and how would we know??
Dina