If you decide that you like Behr Dolphin Fin but really want a Sherwin Williams or Benjamin Moore equivalent, I have a couple of options for you to check out!  Benjamin Moore Stonington Gray has similar undertones but leans to the cooler side of the spectrum than Dolphin Fin does. As for Sherwin Williams selections, Sherwin Williams On the Rocks is very close but has some mild purple undertones. And Sherwin Williams Repose Gray is another great option, but it reads a little softer.