HK I also had a perfect score on that test when I did it about 6 years ago (also quickly). I was confused that all these people who had so much more vocabulary for discussing color than me did not find it easy. I didn't really think that test was a measure of anything more than being able to see well? It was so obvious and easy, I do recall having a couple that troubled me but felt there was no better option than what I had done. You honestly think it comes down to more than decent vision? And a decent screen?
Yes, I think so.  I mean, most people genuinely don't 
see some of those colors as "different" from one another, even side-by-side like that.
Me, on the other hand, I can tell you which ones are the outliers.  From memory.  There are two in the top band, both on the yellow-green side... etc.
I can actually 
see which color selections I'm referring to when I write that, though.  It's my experience that when I do things like that (for example, matching paint chips without reference samples, buying thread of a particular color from memory, etc) other people 
really notice.  So I think in my case, it's only partly better vision.  I think my brain is actually adapted to it somehow, as well.