NARS Nail Varnish in Mash came out in Fall 2010 as part of their Vintage Nail Polish collection along with 4 other colors.
The color is an army green. Green with a gold undertone to it.
The application is light after one coat. I found that three coats gave the best coverage with the least amount of brush strokes showing through.
The application wasn't the best in terms of mid-range nail varnishes but the color is something that I haven't seen before, which makes me think you should snatch this up before it is gone for good!
This is still available at Sephora and NARS as of 11/19/2010.