Put your candy melts in two bowls (keep the colors separate at this step).
Add about a 1/2 tsp of Crisco to each bowl and microwave.
Start with 30 seconds. Stir and then repeat in 10 minute increments. Stop when your melts are 80% melted and just stir and the rest will melt.
In a third bowl or shallow dish ad some of each color and swirl with a tooth pick. I like to do it in small amounts so it doesn’t get too mixed and turn into just one blended color.