This is, indeed, what I was taught about MS. Colors will appear “washed out” and MS sufferers with optic neuritis will fail standard color vision tests, meaning that they are unable to distinguish colors, rather than always call color “A” by the name of color “B.”
Could it happen with some sort of drug use?
Also, I’ve notice throughout most of my life that, in low light, one of my eyes sees colors slightly different than the other. The difference is similar to when you change the white balance or color temperature on a monitor. In one eye, everything has a slightly yellow tint, while the other, slightly blue. I was told by the eye doctor that this was normal.
After being diagnosed and then treated for acute glaucoma episodes (nearly twenty years ago), my colour perception was markedly different in each eye. However, since then I have developed uveitis so the colour problem is less marked than my blurred vision now. Meh. 