Azada chapter 8 second puzzle with the ink bottles

I'm lost on this puzzle. where you have to drop droppers of ink on a piece of paper. Pleas help.

The point of this one is to determine the correct order of 4 different colors of ink. Pick any color (I always start with black, but then I'm methodical). Drop it on the paper. If you get a red x on the chart, then that color is not used at all. If you get a dot that is half green, half red, then the color is used but it's not in the right place. If you get a green check, this color is in the right place.

Each time you get something other than a green check, you have to start over, so go back to the color that gave you the green check in first place.