If you see the word "onion" you have normal color vision. If you the word "color" you are red-green color blind.Being color blind is like living in flatland. You miss a dimension and never notice until someone points it out to you. I grew up making the occasional color mistake but just believing everybody saw green and brown as different shades of the same color.
I have had more official tests that show me fully red-green color blind. I don't see the world in black and white; I don't even have trouble distinguishing red and green. I do see certain color pairs as different shades of the same color: green-brown, blue-purple, red-pink and yellow-orange.
As an undergrad I took a course in computer graphics and they did a demonstration where they showed a colorful picture and then showed three variations where they would turn off one color in each. The instructor said that the original and one of the variations would look the same to a red-green color blind person. Everyone laughed but I went up closely and couldn't tell the two apart.
One day shopping with my wife, she held up two shirts and asked me which one I liked better. They looked identical to me. I claimed she was playing games with me. Now with my knowledge of interactive proofs, I could have tested her: Mix up the shirts behind my back and make her tell me which was which.
My father-in-law is also red-green color blind which means my daughters had a 50% chance of being color blind, a rarity for females. We've tested them and neither is color blind, at least not to the extent that I am.
While color blindness has no cure or fix, it is one of the easiest disabilities to live with. My wife and daughters make sure my clothes match. I have trouble when people give color-coded talks but that doesn't happen often in theoretical computer science. I try to keep colors simple on my own talks and webpages. The Red-Green 3-D glasses don't work for me at all, though the newer polarized 3-D glasses work just fine. I don't usually have trouble at traffic lights but I do have trouble telling blinking red from blinking yellow. If I can't tell from context I just stop, sometimes to the chagrin of the car behind me.
But when I look at art or nature I see one less dimension of colors than most everyone else. I will never know what I am missing.