Looks like crazy ancient flying machines coming to Las Vegas!
I am not sure that I understand what you mean. It is easy enough to get Color from the canvas. I am not sure how or what would be the inverse of a certain color. I may be wrong but I don't think there is anyway to change the Transparency color which is RGB 0,0,0.Just a Selection Tool !
Just to can select one Color on the canvas and make the Invverse selection as a texture transparent on a plan 3D
Can you give me a better idea of your idea