For the GP 1 cup plastic and 10 drops each of spike it GP and GP sp, and medium black flake.
For the "blue", 1 cup plastic, 8 butter knife tips of blue pearl powder, 4 butter knife tips blue hi light powder, 6 drops spike it Flippin blue, butter knife tip pearl powder and just a little bit of medium black flake.
In my opinion, the key to this color is not to make your GP too trans. If you do, you will get green appearance.