In article ,
wrote:
Not a few people -- around 1 in 12 men are red-green colour blind. I'm
not too severely affected, but I have great difficulty telling whether
an LED indicator is red, orange, yellow or green; though I can usually
see the change if I'm watching it. Flashing in a particular pattern
solves it.

Figure an optician friend quoted for the UK was 1 in 3 males with blue
eyes. Something to do with genes. May be different today.

--
*A computer once beat me at chess, but it was no match for me at kickboxing.

Dave Plowman London SW
To e-mail, change noise into sound.