Re: [Phys-l] sun's true color

["Larry Woolf" <larry.woolf@ga.com>]

-----Original Message-----
From: John Clement
Sent: Monday, August 25, 2008 12:02 PM
To: 'Forum for Physics Educators'
Subject: Re: [Phys-l] sun's true color

Well, how do you define color?  
================================

For an objective, quantitative description of color: color is defined by
specifying a color system (most common in industry is CIEL*a*b*), an
illuminant (daylight is CIE D65), and an observer (typically a 2 or 10
degree standard observer).  The color of an object is then the color
coordinates in that color system.

http://en.wikipedia.org/wiki/Color
http://en.wikipedia.org/wiki/Lab_color_space

The color of a blackbody with different temperatures is shown as the
Planckian locus in a color space
http://en.wikipedia.org/wiki/Planckian_locus

To easily convert between color spaces:
http://www.easyrgb.com/


Larry Woolf