Ok here's the situation.
I fly radio controlled turbine powered jets.
Hooked up to the rear of the motor is a spray nozzle where I mist low viscosity mineral oil.
When the mist meets the exhaust at 650C it turns into a huge white smoke plume.
Now what I would like to do is to turn that smoke to different color.
Is it possible?
Red, blue, black?
Is there a chemical that will vaporize at a selected color?