For some reason these make me think of a 70's movie.
There are three polishes in the background and they are all from Sally Hansen's Insta-Dri collection. The base is a bright yellow named Lightening. I used a makeup sponge to add Snappy Sorbet and Flashy Fuchsia. When going for a smooth blend paint all three colors on your sponge (even the lightest base color) and blend like crazy. This took two go rounds with the sponge. The stamp is Konad M51 and Special Polish in Black. Very trippy manicure and this gradient color combo always gets the "How did you do that?".