Essie Lilacism from the Art of Spring collection. I purchased mine for $4 from transdesign.com, but if you need it right now you can get it for $8 at your local Trade Secret or beauty supply store.

This photo is a bit out of focus, but it's the best one to represent the actual color. Lilacism is a milky lavender jelly. There are no pink tones that say "lilac" to me, but it's just a name. The application of this one is decent, not the best but better than a lot of Essie I've tried in my day. The color is definitely pastel but there is a nice punch of soft purple that develops after a couple coats and I really dig this.

Index to pinkie: China Glaze Agent Lavender, China Glaze Light as Air, China Glaze Light as Air, Essie Lilacism