I also don't think there's any such thing as boy colors or girl colors unless we teach our children that there is. Go with whatever colors you want.
That said, babies only see black and white for a couple of months, then they begin to see colors, but have the most luck with high contrast, so brights are relatively easy to see. However, if you want the quilt to last, he will be able to see all colors easily before you know it. Why not make more than one? ;)