I recently re-watched guardians of the galaxy vol.2, and the creature at the beginning could shoot rainbow colored fire. This got me thinking, (as in my spare time sometimes I like to just write a world down. 'worldbuilding' I guess, I'm dumb) is there any way for a biological entity (plant, animal, bacteria, etc) to create a chemical that burns in all colors in the spectrum randomly/pseudo-randomly.

All colors not in a way that makes white, but it splits off in 'sparks' that glow individual colors. I'm hoping for the flame to look similarly in effect to thermite, where there is a main almost fluid flame and many sparks coming off.

Initially I researched this myself as I'm new here and kinda scared to ask in fear of looking stupid. I found what kind of elements burn what colors, like sodium burns orange, carbon/hydrogen burns blue and violet, copper makes green and lithium burns red. Other chemicals as well used in fireworks for example give more specific colors. But I don't know a way to combine these into a single compound/mixture that achieves the effect I want.


  • What I want is a chemical that will burn with a similar effect to thermite, with a flame that glows randomly throughout the entire color spectrum, and produces sparks with random colors too (sparks optional)
  • Amount of heat produced doesn't matter. It can be room-temp, burning or metal-melting temperatures I do not care
  • This 'chemical x' must be able to be produced biologically. Preferably no handwavy methods like 'it just has this certain chemical on hand to produce it 24/7'
  • Feel free to go as nit-picky as you want. If it includes something like quantum randomness that determines the energy of the photon released when the electron jumps to a lower level go ahead.

What is the chemical, how is it made, and what does it look like :) thanks

Extra info:

This is for an alien planet, mostly as decoration for the indigenous people there or some form of mating signal for fauna? idk anyway I'm off track. The life is carbon based with iron blood chemistry. There is about the same amount of resources on the planet as on Earth, however if something needs to be changed let me know. The atmosphere is Earth-like too but with more O2.


1 Answer 1


You can't have a single compound which randomly gives out different emission lines when in a flame.

What you have found with different elements giving out different colors when in a flame are basically emission lines of those atoms: the flame excites certain electronic transition in those atoms, resulting in light being emitted.

Now, those transitions are so carved in stone in their wavelength that we use them to search for elements in remote stars and planets: when you read that scientists have found carbon in the Sun, they haven't been there, but they have observed the spectral lines of carbon in the solar light.

If you put more elements in the same flame, you will excite their emission at the same time, meaning that you will get a mix of lines which will look like a certain color (which color depends on the lines and their relative intensity), and the color will drift based on the temporal evolution of the relative abundance of each element. E.g. if you put together copper and sodium and copper gets consumed first, the green line of copper will fade away.

However in all of this there is little to no randomness. The only randomness you can introduce is the creature to randomly add in the combustible certain elements, i.e. now sodium, then strontium, then copper and so on, so that the color of the flame changes over time. But that's not a single compound.

  • 1
    $\begingroup$ Although I agree in general terms, we can still get different kinds of colour from the same material. The temperature can change it. We can already see this in a normal flame. Take a candle for example, where we can have colourless, blue, yellow and orange. In addition to the randomness, you might have some stuff burn inefficiently, allowing different colours and for it to burn again. That can also add randomness. $\endgroup$
    – Trioxidane
    Jun 9, 2021 at 5:35
  • $\begingroup$ Would there be any way to have the mixture break apart or have a 'controlled steady explosion' where different individual compounds fire off due to the presence of heat and then burn? Also yea, I expected randomness to be impossible but you never know I thought it was worth asking $\endgroup$
    – Alyx
    Jun 9, 2021 at 6:01
  • 1
    $\begingroup$ What about bigger solid particles suspended in flammable material? Looks like logical extension to your answer. $\endgroup$
    – Mołot
    Jun 9, 2021 at 18:01
  • $\begingroup$ @Mołot That was exactly what I was thinking! I was just thinking that maybe the compounds inside the material would be too small or too spread apart to make visibly different colors from each other, and making them more grouped wouldn't give the 'random' colors in the flame. $\endgroup$
    – Alyx
    Jun 9, 2021 at 20:42

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