My initial thought is to bring the blue and grey from the birds to the border with some of the green. I don't know how much of a border you need, but I am thinking along the line of a narrow strip (2-3") of blue, a wider strip (4-5") of the green, and then the charcoal grey (black or white would work too) for the binding. ??? I think you have a lot of yellow and red in the quilt so you don't need to emphasize them more. Bring out some of the lesser colors to make them pop! Do you have some colors available to show us?