Pour each chocolate in a glass, microwave safe bowl.
Line baking sheet with parchment paper.
Starting with the semi-sweet chocolate, put in microwave for 60-90 seconds stirring half way through until melted.
Pour onto parchment & spread out to a thin layer.
Next do the same with the white chocolate but instead drop in spoonfuls all over the top of the semi-sweet chocolate.
Then do the same as the white chocolate with the colored melting chocolate.
Take a skewer or stick of some sort to pull through to swirl the chocolates together. ( I used a chop stick)
Sprinkle the nuts over the top & press in just a bit.
Transfer to freezer for 30 minutes to set.
Remove & stab with a sharp object in random places to break apart.
Store in refrigerator for up to 1 week.