Path: utzoo!mnetor!uunet!husc6!rutgers!lll-lcc!well!wcalvin
From: wcalvin@well.UUCP (William Calvin)
Newsgroups: sci.misc
Subject: Re: Color
Message-ID: <4673@well.UUCP>
Date: 9 Dec 87 07:51:20 GMT
References: <8VicPfy00Xo3QHM08t@andrew.cmu.edu>
Reply-To: wcalvin@well.UUCP (William Calvin)
Organization: Whole Earth 'Lectronic Link, Sausalito, CA
Lines: 12


Color hues are basically a function of the relative activity in two
cone types, e.g., the ratio of "red" cone to "green" cone activity gives
yellows whether it is accomplished by a 540 nm pure wavelength or a
mixture of 500 and 600.  But red and blue cone absorbance curves don't
overlap enough so as to produce some ratios with any single wavelength
stimulus.  The ratios produced by a 400 and 700 nm mixture are not
unique but they cannot be matched by a single wavelength.  We call it
purple.
		William H. Calvin
		University of Washington NJ-15, Seattle WA 98195
		   wcalvin@well.uucp    206/328-1192