Chris, I haven't seen my suggestion talked about so far. My DH is red/green color blind. I have found color to be a most interesting topic when it comes to what looks good to him.
Is your quilt a surprise to him? If it is not, why not have him go with you to a fabric store or a clothing store to explore colors? My DH sees blues and yellows very well. My favorite color is hot pink and I wear a lot of it. He sees it in blues since hot pink is made up of blue pigmant. Pastels become kind of a wash out and look mostly white to him. Quite often, even a red will look good to him. I love having him go with me to my LQS to look at fabrics. You might be surprised.
I think you are a sweet Aunt for considering how he will visually see your quilt. I bet you are learning a lot about color because of the gift you are making for him. Bless you, Linda :-D