i will tell you how to do it. It is easy.
Take a little 2" wide container of water.
Drop nail polish driop by drop onto the surface. It will make a bullseye of color. Drop a total of nine drops using at least 3 different colors. Take a toothpick and draw lines across the bullseye making a swirl.
Dip the nail into the color. The film of color will cling to your finger tip and nail. Use nail polish remover abd a Q tip to remove the extra polish.
Clear all the old bits of film out of the water to prevent lumps. Work quickly. JP