It's a hard one for me to describe as it seems to change depending on what kind of light you are in. In bright light it can look grey, but in general I'd describe it as taupe, mushroom, greige, concrete....!?!
It's a great formula, being totally opaque in two coats and no streaking. As I use a topcoat, my nails always look shiny, but I've had two people on two separate occasions asking if they are gel as they are so super-duper shiny.