Good Morning,

This is not just a simple paint. This has a texture to it and has movement to the color. This looks like it may be a matte plaster.

So if you are this done professionally, I would ask them to bring you samples of matte plasters in grey so you can see how different grey look in your space. If you are doing it your self, you can check at your local paint store and ask them for recommendations on which product to use and possibly see if you can take a class on how to apply it.

Good Luck!

-Cosa Belle Interiors