Nocturnelle is described as a "pinked-up chrome purple [with a Frost finish]." It's a brightened, medium-dark purple with cool, pink undertones and a satiny sheen. It had fully opaque color payoff, and the texture was fairly soft and blendable. This shade stayed on well for eight hours. See swatches of all dupes / view dupes side-by-side.
FURTHER READING: Formula Overview, which is a detailed review of the range as a whole.