A post I made elsewhere concerning colors according to alien eyes:
Indeed so, even if they happen to use the same chunk of the EM spectrum we do as “visible light”. There are, I suppose, some restrictions on what’s likely, since moving too far into the longer wavelengths starts to give you resolution problems and moving too far into the short wavelengths gives you issues once you start trying to come up with plausible eyes that run off ionizing radiation, but even so. The eldrae, for example, whose visual spectrum stretches a little down and a little further up from the human one, have three colors we don’t: gallé (infrared), ivén (low UV), and serís (high UV); the kaeth, by contrast, have two infrareds, no UVs, and can’t see the wavelengths we call “violet”, either. And that’s before we get into all the subjective issues of how the actual qualia differ, if that’s even a question that’s possible to answer.
The standard interlingua has a set of compromise color names defined by the frequency bands of the light in question, specifically to help sort out this whole sort of general mish-mash with which colors look like what to whom, once all the optical system differences get sorted out. (Consult your friendly translator’s test card for what each color looks like to you!)
Of course, where life gets really interesting is that the human visual system, due to its architecture, innately does some averaging inasmuch as it can’t tell the difference between red-and-green and yellow in light, or between blue-and-yellow and green in pigments; the brain never gets that data. But there’s no reason that a visual system has to work that way, although I assume in my universe for various implementation reasons most of them do – so, imagine how wildly different the world would look to someone who sees all the different mixed pigments/lights we use to produce that shade of green as entirely different colors, and the same for every other shade…
(And then try and imagine using one of their control panels – quick, is that the yellow alarm light flashing, or the red-and-green one?)