1. Total blindness
This one’s a gimmie. Of course you can’t see colour. You probably can’t see gender or sexuality either. We’d tell you to consult a doctor but chances are if you can see literally nothing you are probably aware of the fact and have sought the appropriate help.

At this point, Neo could not see the difference between the red and blue pill. Source: Universal
2. Monochromacy
While many forms of colour blindness affect specific colour patterns (the most common being across the red-green colour spectrum) there are forms of visual impairment which render the sufferer completely unable to distinguish between any hues at all.
While very rare among the general population, the disorder affects about 10 per cent of the population on the island of Pingelap, part of the Pohnpei state of the Federated States Of Micronesia. The island was devastated by a storm in the 18th century and the recessive gene carried by one of the few male survivors.
So if you’re from Pingelapese, it’s reasonably likely you can’t see colour. Although to be fair, you should still be able to distinguish between shades of brightness, so it may be possible for you to make an informed guess.
3. Face-blindness
Face-blindness, also known as prosopagnosia, is a rare cognitive disorder where the ability to recognise familiar faces, even one’s own, is impaired, despite all other aspects of visual and brain function remain intact.
While people living with prosopagnosia aren’t technically colour-blind, levels of co-morbidity are estimated to be as high at 72 per cent.
So here’s a quick test: look in the mirror. If your immediate response is, “who is this person and what are they doing in my bathroom?” there’s a fair likelihood you suffer from prosopagnosia. That being said, you should probably call the police anyway just to be on the safe side.

Nobody here can see colour at all - just different shades of blue. Source: The Feed
4. You’ve just looked at an eclipse
Oh, dearie. Didn’t you know this was a bad idea? Staring directly at an eclipse causes a condition known as solar retinopathy, where the retina is effectively flooded with light.
Thankfully, the damage done is often temporary, so you should be back to seeing colour in no time!
5. You’ve got something in your eye
Having a foreign object or substance in on your cornea often leads to a brief inability to see out of that eye, or indeed to open your eyes at all. You should still be able to see properly with the other eye, although your depth perception will be impaired.
If you’ve been unfortunate enough to get something in both your eyes, you may be temporarily unable to see colour. Flush your eyes with water and if pain persists, please see your doctor.

Proof Source: Comedy Central
6. Ignorance
Owing to either a lack of education, an isolated social upbringing, or a sheer bloody minded refusal to acknowledge the reality of the world around you, you may well be under the impression that you don’t see colour, and that the inequality see you see perpetuated across regions and generations is just an unfortunate coincidence and not the result of centuries of systemic oppression.
Thankfully, this one is pretty easily fixed. Chat to a few people, read a few books, and open your eyes.