Try asking the designer a question. Go back to the image you saw this on, and look for a tab marked “ask the designer” then ask your question. They are best positioned to give you a reply.

You can also find any kind of color at: www.pantone.com or www.ralcolor.com
Good luck

Maybe mint-something???

http://www.benjaminmoore.com/en-us/paint-color/imperialgray

If you click on the photo on Houzz, where you found it, you can often find more info and you have the opportunity to ask the designer. I've looked for you and the colour is Imperial Gray by BM, see link.

Even if someone were to tell you the exact color, it might not be what you thought when you see it in person. For that reason, you would be better off just going to the store and getting a bunch of swatches that are similar and bringing them home to try out in different lights and at different times of the day.