I want to be able to explain: the coloration of my planets when I create them, but I don't have enough knowledge on the colors of elements or chemical compounds. I have done extensive research into emission spectrum and spectral lines, colors of common compounds, etc. but nothing is straightforward.

Hypothetical Example (do not need answers to these): Planet x is green with purplish swirls. What could it be made of? What causes the green color? What caused the purple color? Could it be neon gas? Could it be chromium (III) sulfate?

What I need: I need a resource to help me creatively explain what kind of compositions yield certain colors. I don't want to have to ask a new question for each of my planets.

Good answers will: Provide a link to a resource dedicated to the colors of elements and chemical compounds (even so-called "clear" elements and compounds would have a distinct color on a planetary scale)

An example of a somewhat decent answer is: https://en.wikipedia.org/wiki/Color_of_chemicals

However, I am looking for a list that is bigger and more detailed. Preferably a robust list that could tell me, for example, what colors different elements are in different states of matter (solid, liquid, gas).

  • 2
    $\begingroup$ Please, one question per question. Please take the tour and check out the help center as suggested, and edit down to a single question per post. Voting to put on hold as too broad until the edit. $\endgroup$ Sep 13, 2019 at 16:34
  • $\begingroup$ Just grab any book or website on the topic of gems, or mineralogy, and you'll get more than enough info on inorganic materials. $\endgroup$ Sep 13, 2019 at 16:48
  • $\begingroup$ I don't want a book. And a topic on gems and mineralogy wouldn't help me explain colors of liquids and gases. $\endgroup$
    – overlord
    Sep 13, 2019 at 16:51
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    $\begingroup$ What you want to know here is an entire field of science. You could of cause use the Sudarsky's gas giant classification for gas-giants and maybe of ice-giants. This video about sky and plant colors should help as well. Outside of that, just look at the solar system's planets, pick the one most similar to your fictional world in terms of mass, composition, and illumination. Modify the looks and don't go too crazy. $\endgroup$ Sep 13, 2019 at 19:33
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    $\begingroup$ The only requirements for a good answer for this question was that I be given a resource that is better than the list I already have. It did not need to be complete or nearly complete or even close to being complete $\endgroup$
    – overlord
    Sep 24, 2019 at 12:55

1 Answer 1



Gas, Color
- Helium: White to Orange; under some conditions may be Gray, Blue, or Greenish-blue.
- Neon: Reddish-orange
- Argon: Violet to Pale Lavender Blue
- Krypton: Gray, Off-White to Green. At high peak currents, bright Bluish-white.
- Xenon: Gray or Bluish-gray, dim White. At high peak currents, very bright Greenish-blue.
- Nitrogen: Similar to argon but duller, pinker; at high peak currents bright Bluish-white
- Hydrogen: Lavender at low currents, Pink to Magenta over 10 mA
- Water vapor: Similar to hydrogen, dimmer
- Carbon dioxide: Bluish-white to Pink, in lower currents brighter than xenon
- Mercury vapor: Light blue, intense Ultraviolet - Sodium vapor: (low pressure) Bright Orangeish-yellow https://en.wikipedia.org/wiki/Gas-discharge_lamp

Liquids (At room temp)

  • Gallium (silver)

  • Bromine (Reddish-orange)

  • Mercury (Silver)

  • Francium (as a solid) (Reddish-orange)

  • Cesium (silver)

  • Rubidium (silver)


List of solids, liquids, and gases.



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