What a wonderful quilt! You'll need to STID to anchor it anyway, once you get that done you might have a better idea of what you'd like, but I agree with QuiltnNan an all over meander in a neutral color (and in this quilt a paler yellow would be neutral) will be good. My go to neutrals are usually a shade of gray or tan. If it's going to get washed fairly often I would definitely go with an all over design. Such a great quilt design and fabric choices!!