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).