lynnie

black will contain it nicely like a picture frame.

Cactus Stitchin

Black would work but believe Sewnoma expressed my thoughts best. Since black isn't in the quilt top I find it adds to the brightness and would probably opt for either the blue or gray. It is definitely a matter of preference and might depend on what you are using for the backing.

EasyPeezy

I'm leaning towards grey. Why don't you put different fabrics next to it?
Take a picture then decide which one you prefer.

zozee

Grey gets my vote for aesthetics and practicality. White would be harder to keep clean on a daily-use quilt.

jokir44

To my eye the black will give your quilt a modern look that goes well with the geometrics.
If your intent is more traditional I would go with the blue.

costumegirl

Very pretty top!! Fresh and bold!
I think the binding would depend on the backing that is used so that it enhances and compliments the bold look of the top. I would probably use white or grey.

bearisgray

At first, I thought the dark gray.

Now I think I would like the red.

jillmc

Great quilt! I would try the grey.....

ruby2shoes

My Hexactly quilt was the same...very bold in your face colours and lots of dramatic white space. I first tried a red binding but found that it took the eye away from the quilt so replaced it with a white binding which I feel resulted in a much more dramatic and modern effect.

cathyvv

maybe the blue would be good. Love the quilt!