I agree with DogHouseMom. Since your quilt is a scrappy, you have a lot going on already. The yellow is busy also, so I think it would be too much. The dark blue makes a great "stop" border, then the green calms everything down, and also pulls from the inside of the quilt. Try laying it out as she suggested and see what you think. By the way, the quilt looks great.
Darren