Here's the thing, if you wave something green in my face, I am not going to say "stop waving that red thing around", I have bought a pair of black pants once and had people say "why did you get navy blue? You should have got black". If I look at something red on a green or blue background, the 2 colours will dance around like crazy, and when looked at those discs in school, I saw absolutely nothing but a random jumble of circles.
This is from the BBC website, apparently there is a number 6 in it - for all I know, it could have the most obscene messege ever written, it is nothing but random circles to me.