Panasonic KX-P8420 Manual

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Chapter 5
53
Working with Color
This chapter introduces concepts that are basic to color theory. You will 
encounter some of these concepts (such as hue, saturation, and 
brightness) when you work with color in applications; others provide useful 
background information. 
Color is a complex topic, so consider this a starting 
point for experimentation and further research.
The properties of color
What we call “color” is really a perceptual ability unique to humans and a 
small number of animal species. Color theory is an attempt to systematize 
the properties of color perception, which by nature is relative and 
changeable. A color appears different depending on the other colors around 
it, and individuals vary in their abilities to perceive color. 
The human eye can see electromagnetic radiation at wavelengths between 
400 nanometers (purplish blue) and 700 nanometers (red). This range is 
called the visible spectrum of light. We see pure spectral light as intensely 
saturated or pure colors. Sunlight at midday, which we perceive as white or 
neutral light, is composed of light from across the visible spectrum in more 
or less equal proportions. Shining sunlight through a prism separates it into 
its spectral components, resulting in the familiar rainbow of colors.
Like the sun, most light sources we encounter in our daily environment emit 
a mixture of many light wavelengths, although the particular distribution of 
wavelengths can vary considerably. Light from a tungsten light bulb, for 
example, contains much less blue light than sunlight. Tungsten light 
appears white to the human eye which, up to a point, can adjust to the 
different light sources. However, color objects appear different under 
tungsten light than they do under sunlight because of the different spectral 
makeup of the two light sources.
The mixture of light wavelengths emitted by a light source is reflected 
selectively by different objects. Different mixtures of reflected light appear 
as different colors. Some of these mixtures appear as relatively saturated 
colors, but most appear to us as grays or impure hues of a color.
The physics 
of color