This question on Scifi.se: Why does warp plasma burn green? mentions a fictional type of plasma called 'Warp Plasma' that is capable of igniting and when it does it sprays plasma flames/gas out of pipes as if it were oil or some other form of fuel.
Wikipedia says that the sun consists of hot plasma interwoven with magnetic fields. I couldn't find anything about plasma ignition (This is what I originally thought might be a reason why stars are so bright).
Is plasma capable of igniting?
Best Answer
Plasma is a kind of matter very similar to gas in which atoms have been ionized. It is very hot and lets off radiation (also in the visible spectrum) due to recombination so it might already be considered flame. Thus it isn't clear what "igniting plasma" really means.
In cold plasma where only a small fraction (few percent) of atoms have been ionized you can have normal chemical reactions (aided by plasma's high temperature). Example of such a process occurs in plasma created by lightening and produces ozone (O3). Thus mixing in the right chemicals can result in oxidation occurring within plasma which could be considered burning. For example plasma made up of element which easily oxidizes could be affected by mixing in gas oxygen. I guess it could be considered ignition, but it seems a stretch relative to the ordinary meaning of the word since even cold plasma is already very hot (few thousands degrees Celsius) and causing oxidation to occur inside such plasma would not add a lot of heat (in relative terms).
As for the color, careful engineering can produce plasma where recombination energy is such that light of a given color is emitted.