After learning about the different types of color blindness and what causes them I discovered that one of my friends was color blind. During the weekend he and I were talking about how people saw different colors and as I was telling him how the system works we began analyzing different objects in the room and stating what color we thought they were. I initially made the mistake of asking him what colors he could not see, to which he quickly responded how can I tell you which colors I can’t see? After he said that I began to think about the way the color opponent theory worked and how I could apply that to tell him what colors I was seeing. At one point we were both arguing about the color of this candy wrapper that was sitting on his table. He looked at it and said it was green. And then I proceeded to ask him what type of green it was. He was baffled by the question. He could not tell the difference between different types of greens because he only knew what green was based on what he has been told throughout his life. The green color we were looking at was actually much closer to being yellow than green. Just to confirm his inability to differentiate between shades of green I asked him how he would mix paints to make the color we were looking at. He told me that he would have no idea how to make that color if he tried. This made me wonder which color was missing in his perception. Since he could see that the object was green but also could tell there was yellow I concluded that he was unable to see blue. The most interesting part of the experience was that he knew the color was green but he didn’t know why. In his eyes the color was clearly different than blue or yellow but he was unable to distinguish between different shades of green. Although I am not a doctor or have any training beyond what I have learned in this class I told my friend Kevin that he might in fact be a Tritanope. I explained to him that a Tritanope is someone who suffers from a lack of S-cones. I also explained to him what the other types of color blindness were in case he disagreed with my thoughts. Because he is a stubborn person he disagreed instantly, so we then proceeded to do online color blindness tests. He completed all the tests, and then when we got to the test that includes a 42 that consists of red colored dots and a background of different green dots, he was unable to see the number in the middle. After failing this test I realized that he was not a Tritanope. According to what we found while doing our internet search people who were unable to see the red 42 on the green background were Deuteranopes. This meant that his deficient cones were in fact the M-cones. This diagnosis was confirmed by his inability to properly perceive colors that were bright green with yellows. Being color blind has never affected my friend’s life, other than his inability to dress himself and match colors (which truly doesn’t matter). I think it is rather interesting how he has been able to adapt his whole life to what colors he has been taught without ever noticing that he could not see certain colors at all.