they are great blocks ... I have to say I love color so a splash might make your blocks pop. But when it comes down to it, what do you like? After auditioning a couple colors for sashing or borders, you may decide you like it just the way it is... : )

I was a thinking maybe a red tiny flowered print Flange? Then add border using one of the fabric used here?

To me, it screams for a little pit of color. Maybe a tiny thin border before the final border, or the binding in color?

Are going to make more blocks? What about having just ONE block where you replace some of the black and grey with a colour, my preference would be red, and then bind the quilt in the same colour?

This is exactly what I was thinking! A thin border of red or lime green and then a larger border of the focus fabric, maybe? Make sure you show us what you decide to do!

I would try various color using what scraps you have in your house. Personally, I would try something softer like an aqua because I would worry that the red might be a little to powerful but try it too.

What about a red (or other color) flange tucked into a border that is a continuation of the monochromatic color scheme? Perhaps a binding in the color of your choice. Perhaps the back of the quilt could be in that chosen color. I really like the blocks; they make a lovely quilt-with or without an additional color.

I would only add a color border if I replaced a few of the block pieces with color as well - just enough to tie it together. Most any bright color (bright pastels are my personal favorite- lime, coral, aqua....) would work and keep it looking modern.

You could consider putting some piping in between the last border and the binding. You could use a nice bright color and it would pop. This way you get a tiny bit of color that doesn't overwhelm. LOVE the quilt so far!

You don't need color in it , unless you want to change the color scheme. I like as is, Now if you want color to make it pop, bright yellow, turquoise, red or royal blue would be nice.