So, first I painted my nails with a base coat then the light green in the pictures.
Then I took my sponge brush ( a cheap one) and dabbed the green polish on again, but this time only the tip of my nails.Next, I mixed a teal color with my green.
Then I dabbed the resulting color on the middle part of my nail.
For the bottom of my nail, I dabbed the teal color alone. You're fingers are going to get a fair amount of polish on them as well, but don't worry, all you have to do is take a Q-tip and dip it in nail polish remover to remove the excess on your skin. As seen below.
Bam! Tri-color nails and super fast and easy. once they dried, I put a top coat on too. And you can do it with whatever colors you like.