Green with Envy is a very dark green creme, like a school blackboard. It is very dark green but for me never looked black, but perhaps that's the view of a polish colour obsessive!
This swatch is 2 coats, the formula was great and look how shiny it is without a topcoat.
Overall I think the Avon's are good quality polishes, with somewhat unusual colours for a great price (on sale) - but actually not a bad polish for the full price either, especially given the size of the bottles.