I think I would use red!

I go with blue unless can find a stripe with all the colors and then cut the binding on the bias.

It just depends on what you like. If you like the bright binding, then make sure you seams are all pressed OPEN and cut your binding strip. If you don't want your eye to go to the binding, then use the blue. The quilt came out real cute.

I think you have enough interesting things going on that to add a visually-busy binding would be too much. Go with the blue-- that allows the focus to be on the cute bird and flowers.

Multi color!!!!

I don't think the blue of the bluebirds would be a good choice for the binding. Do you have enough of the outer border blue to use that? I like the idea of the multi-color border, but the question is, would it detract too much from the quilt center. Can you try a mock-up of the colorful binding and take a photo? Photos can be so helpful.

I would use the same blue as the border - it frames the blue bird and flowers and doesn't distract from them. I think the multi-color border would pull your eye to border and not let you see the center which is focal point.

I like the blue but wondered about using the brown of the twig holding the bird.

The quilt is darling. I would bind it with the blue as my first choice. Second choice would be WOF strips of the flower colors. If is a baby quilt I would not add buttons to the flowers. I would sew or embroidery a center to the flowers for safety.

I think a multi-colored binding to match the multi-color in the other border stripes would be gorgeous. Just be sure to have the seams on the bias and pressed open as others have said. No need to cut strips on the bias. It will be a lot of work, but I think you would be rewarded by the results.