The Uptown is a purple jelly based multi-coloured flakie polish. I think you could achieve opacity, or close to opacity, but I put it on top of China Glaze's Scandalous Shenanigans, a beautiful sapphire blue. I love the effect of of this flakie.
This is the only polish I picked up from the 2013 Fall Girl About Town collection...the remaining ones never really caught my eye.