I recently got a few soak off gel polishes from Madam Glam, including some magnetic gels! This is Always Together. They recommend using these over a black base, but I decided to do three coats alone. I used their magnet on each coat to get the gold magnetic stripe effect.
The pink sparkles have a golden duochrome effect:
On my thumb I alternated Always Together with another of their similar magnetics, Viva Drama, which has blue-to-purple sparkles (so this is four coats total, two of each polish).
I used Madam Glam’s peel off base coat under these. It works well, but I haven’t been able to get it to work for me, in the sense that I always get bubbling under it so far! It doesn’t show here since the sparkles camouflage it… Not sure yet what the issue is!