Peam just finish his version of street fighter puzzle and I while i was playing with him, I had problem detecting a yellow gem from a green gem. I can detect, but hardly. I have to adjust the color value of the gem a bit so that I can clearly distinguish green from yellow. That is quite strange coz other guys in the lab can tell which one is green or yellow very easily.
So I took Ishihara Test, and it turned out that I am a color blind :O. Furthur investigation at wikipedia reveals that I am a kind of protanopic, i.e., having problem with the red color (so that I have a problem telling yellow and green apart). On the Ishihara test, i pass 4 out of 6. I cannot answer the number in the bottom test. Well, there are two kinds of protanopic, protanomaly and protanopia. The first one is anomaly, i.e., lesser sensitivity to the red color (both saturation and brightness) while the other is completely red defunct. I am protanomaly (the web said that it is about 1% of male population for white ppl.) Most color blind people is Deuteranomaly, green-weekness.
Now I remember that I had this Ishiara test before since my junior high, I have problem at that time too but never take it serious, (well, the code plate must be bad so that I cannot tell the number while the other can, what an ego of me hahaha). Back to my high school when I was playing the real street fighter puzzle with my dear Nick, I have problem also but again I blame capcom for not making the yellow and green one more distinguishable hahaha.
here is the test on wikipedia, this one, I cannot tell the number.
However, for this one, I clearly see the number, I can see it very very clearly while the others in my lab can tell, but not clearly, strange, though.
How clearly, you may ask. Well, let just say that, for me, it is clearlier than this picture. Everyone, color blind or not, should be able to identify the number in this picture.
This one is quite an informative article http://webexhibits.org/causesofcolor/2.html
Finally, I am lucky that I am Anomalous Trichromacy. For my protanopic case, it is called Protanomaly which means that I know all the color but having problem discriminating color in green-yellow zone. I know what is red, (at least, i agree that this object is red when other ppl do so) but saturation and brightness of my red is lesser than normal ppl. With low enough red value, i cannot separate it from black.