It's a beautiful quilt and I think picking up one of the darker blues in the tumblers would finish it off quite nicely.

Red gets my vote. I think it will make all the tumblers pop.

A red/blue combination would look good with the blue predominant--a bright perky blue/red combo.

I would go with the medium to dark blue. It will set off the colors mush as your suggestion of red would do. Yet, the dark to medium blue will blend and complement the colors of the quilt.

The dark blue would be nice to stop the Tumblers from falling off. Ha Ha ! ! !

Wow, that's a big quilt top. I think dark blue would be a good choice also. The quilt is beautiful!!!

For the binding I would select a blue-green or a blue-purple; OR a pure red would really be outstanding.

Wow what a beautiful quilt!!! I want to make one for our bed in the same colors but different pattern :)
I would choose dark blue.

I usually prefer to use a darker color because the binding will be the first to show any dirt and wear.

I would use a dark blue, I think it would look like a frame.