Re: Screen colours (was: HUMOUR: If Craig Shergold Wrote Dr Seuss Parodies...)

[David Jones/KSBEISD <David_Jones/KSBEISD -dot- KSBEISD -at- DATAHUB -dot- COM>]

scot @ HCI.COM.AU said many interesting things, including:
>I saw an interesting doco (ITV? BBC? Channel 4? I don't know but it was
English) a few weeks ago about Traffic. During the discussion of this, the
evolution of the Traffic Light was discussed. Where do the Red and Green
lights come from?

After a number of serious steamship collisions in the Atlantic, it was
decided that all ships where to carry identifying lights. But what colours?
Experiments showed that red and green were the two most easily
distinguishable (yes not including those with Red-Green colour blindness,
which is 4% of males!) and -brighest- colours that they could use. Thus, Red
for Port and Green for Starboard was mandated. Traffic lights followed this
convention, except Red  meant stop and Green meant Go (Yellow was added
later after it was shown that motorists needed some indication that the
lights where about to change -- oh and BTW the signal -positions- indicated
to those who were colour blind). I would suggest that our Red/Danger -
Green/Safe connotations have nearly entirely flown from this signalling
decision, which is to say, it's entirely cultural, and not necessarily
universally understood.<

I suspect this may be built into human biology by millenia of life, where
seeing red blood might indicate life-threatening injury of self or another
member of the tribe, or weakening of potential prey. And green might indicate
plant life offering a place of concealment. I've heard it hypothesized that
humans original developed their carnivorous practices as hunters that chased
prey until it was too exhausted to run or fight ...

I've heard that fire fighting vehicles have switched from red to yellow or a
yellowish-green because it is easier to see against cluttered backgrounds.

Red/green is nice, but on a computer screen, I prefer something active, like
blinking text. I suppose, in the future, that computers will get our attention
with built-in voices, "Hmm, excuse me, but did you really mean to do something
so stupid?" <G>

David Jones, Technical Writer
David_Jones/KSBEISD -dot- KSBEISD -at- Datahub -dot- com
Kamehameha Schools Bishop Estate

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"I do not speak for my employer, my computer, or any other living thing."