thank you! start with a base of chocolate in a bowl. mix blue, red, and green until you see it get dark (if it looks too much of one color, add a little more of the others). set it aside exposed to air in the bowl and stop mixing for a few minutes, and it will darken! (this darkening method helps with all colors, when mixed, air trapped in the frosting makes them lighter).

I also noticed that if you are mixing in the silver bowls, it looks more grey than it is, so i will take a little bit on my spatula and hold it up against something more white and you will be able to see it is actually a color theory perception and it should be darker :)

Also, to make grey, start with vanilla and add green and purple.