I scored "22" the first try - with a likely perception deficiency in a pinkish part of the spectrum. My wife would probably have guessed it to be much much worse ;0)
But... I tried it a second time and concentrated real hard and got an "8". Whoo hoo! I'm not as perception deficient as we'd thought.
Phew! That's like work though. I don't think I'll give it a third try! I just be happy with that 8.