According to the Barielle site Decadence is 'turquoise metallic.' I'd rather call it teal, it can be very close to green depending on the lighting.
Barielle Decadence applies fairly well; it's a bit thicker than I prefer, but with the right amount of polish spreads well. The opacity is very nice, I applied two coats can barely see the tip.
And here's another photo, out of focus to show some sparkle:
I love the colour, and with a few drops of thinner I might love the application, too. It's not an everyday colour for me, however.
How do you feel about Decadence?