I really 'love' the quilt just the way you have it.
I don't usually suggest, but if I had one like that, I think I would use some red to make it 'pop' then add black binding.
I'd use a light blue light weight chambray for the back instead of real denim. I agree, I hink it has enough of a border already, but if you add a border, definitely bind in black - it's worth an Oscar!!
Hmmm I am thinking if you have any or enough of the yellow with the stars, it would make a bright border and make him think he is a Star film maker! :)