Pour half of the green mixture into the prepared pan (about 1/2 cup). Place pan in refrigerator to set, about 10-15 minutes. You'll know it's set when you can lightly press down with your finger and it feels solid (as if you could pour something on top), but still sticky. Once the green layer is set, add half of the yellow mixture, and return to the fridge to set. Repeat with the purple layer, and then repeat all 3 colors once more. (A total of 6 layers). Allow it to set overnight to completely bond and set up properly.