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From: info-mac@utcsrgv.UUCP (info-mac)
Newsgroups: ont.micro.mac
Subject: None
Message-ID: <4311@utcsrgv.UUCP>
Date: Thu, 17-May-84 01:52:33 EDT
Article-I.D.: utcsrgv.4311
Posted: Thu May 17 01:52:33 1984
Date-Received: Thu, 17-May-84 01:58:55 EDT
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Organization: CSRG, University of Toronto
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Date: Tue, 15 May 84 18:51 PST
From: uw-beaver!DENNIS.GRIESSER@HIS-LA-CP6.ARPA
To: INFO-MAC@SUMEX-AIM

About the program for color on the MAC...

A few transactions ago, somebody posted a program that displays color
on the Mac.  Very little documentation was provided.  Although I don't
have a Mac, I know a little about the technique that was used.

It's called "subjective color".  It can be produced on monochrome (!)
displays by flashing the item to be colored on and off in a certain
sequence.  There is really no color there, and a camera won't show
colors.  It's all done by tricking the eye and brain.

Some people who are normally color-blind have no trouble seeing these
subjective colors.  Some folks with perfect vision can't see one or
more of the subjective colors.  I don't know what factors are involved
in who can and cannot see this effect.

This phenomenon has been known for years.  It is usually demonstrated
by spinning a disk that carries strategically spaced dark and light
areas.  This is the first I have heard about software to produce
subjective color.  Some proposals have been made for hardware to
produce this effect, but I have not heard of a commercial product
that uses it.

For the insatiably curious, there was a good article on this topic in
BYTE many years ago.  Try looking around 1977.