all about the chemical makeup of an object.
The technical term for color fading is photodegradation. There
light absorbing color bodies called chromophores that are present
in dyes. The color(s) we see are based upon these chemical
and the amount of light that is absorbed in a particular wavelength.
Ultraviolet rays can
break down the chemical bonds and thus fade
in an object - it is a bleaching effect. Some objects may be more
prone to fading, such as dyed textiles and watercolors. Other
may reflect the light more, which makes them less prone to fade.
Kurt. The Physics and chemistry of color: the fifteen
causes of color. New York: Wiley, 2001. 481 p. .
more print resources...
Search on "Color,"
"Dyes and dyeing chemistry," or "Light"
in the Library of Congress Online
What is ultraviolet light? From "Ultraviolet:
the Science Behind the Medicine." ClarionHEALTH, c2000.
Of the three types of energy contained in sunlight--ultraviolet
radiation, visible light, and infrared radiation--ultraviolet (UV)
can be the most dangerous. From "Cool
in the Shade," Texas A&M University.