Behind door 14 is a little Halo bottle of polish. This is what I had been hoping for when I peeled back a door the other day only to be disappointed by a pearlescent polish. Halo is a special topcoat polish, changing whatever polish you are wearing underneath.
I used NYC West Village 204B as the base, left the thumb without the Halo as a bit of a comparison In the photos it makes the blue lighter and more metallic duochrome looking, in the indoor dark of the British winter it looks a lot more purple with a duochrome shift than the blue. Very much a petrol on water effect.