After reading the posts here, I picked up my Rock paraty to check on the coloring. Haven't brought her out in a month...but man.... do I LOVE this bag! It is my favorite bag ever! The color and shape of it is just perfect. I'd describe Rock color as dark taupe. If you girls have taupe eyeshadow, you'll know what I mean when I say that Rock definitely has that warm shade of grey which can sometimes seems brownish (just like taupe eyeshadow).
ITA, it is like a dark grey with just a tiny bit of brown undertone. Just a gorgeous color. To me, it's more of a grey than brown (I'd say 90% grey + 10$ brown)