How to add a color to vapors?

I want to add a color to vapors, like the vapor that comes out of glycerine when heated.


Is there a chemical compound I can put into glycerine that makes the vapor colorful? Or is there a chemical compound over which I can pass the vapors and they get colored?




By means of physics, just vaporise the glycerine and shine light on the vapours -- like it is done for [water curtains](https://www.youtube.com/watch?v=xb-gfTMtgu0). Similar results may be achieved with fog machines ([here](http://www.ehow.com/how_4911741_make-colored-fog-solution.html)). The advantage: your light source defines when and what kind of colour is visible behind a dark background / in a darker environment. To quote from a lecture by French chemist Hervé This: "Egg white appears only white because of the white light normally used in the kitchen, as soon we use red light it were egg red."


[![enter image description here](https://i.stack.imgur.com/fhCuS.png)](https://i.stack.imgur.com/fhCuS.png)


([picture source](https://www.flickr.com/photos/crimson-haze/15622136370/in/album-72157649196138515/))


If, on the other hand, you want to use chemical means, mix glycerine, water and appropriate food colours, and evaporate it in a fume machine. A how-to like [this](https://www.craftsuprint.com/projects/crafts/various/how-to-make-colored-fog.cfm) may be a good starter.


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