131
Chapter 4 Perspective, Scene Design, and Basic Animation
CASE STUDY
In this example, the HSL color model is used to define
orange.
Goodheart-Willcox Publisher
Digital Color Models
To create the millions of colors we see
in real life, computers need to mix basic
colors. In Chapter 1, you saw how the color
wheel allows you to mix the three primary
colors (red, blue, and yellow) to create the
complementary and contrasting colors.
Digital color models are similar, but slightly
different. Two common digital color models
are RGB and HLS.
The RGB, or red, green, blue, model combines
three colors in different densities to create
different colors. The RGB color model is
used on most personal computers, television
sets, LCDs, and handheld devices. These
display screens can easily blend the three
color components to create white, black, and
millions of colors in between. The bit depth of
the color (8 bit, 16 bit, 32 bit, etc.) determines
the number of colors that can be created.
In the RGB model, a color value of 0,0,0
(red = 0, green = 0, blue = 0) is black, as
shown in the figure. This makes black the base
This is the Colors dialog box from a Microsoft
Office application. In this example, the RGB color
model is used to define black.
Goodheart-Willcox Publisher
color for the RGB model. So starting with black,
when you add red, blue, or green in different
densities (values), new colors are created. If you
add a maximum amount of red, green, and blue
(255,255,255), the color is white. The maximum
amount of color that can be added is 255. Every
digital color can be written in RGB format.
The HSL model uses hue, saturation, and
luminescence values to create colors. The hue
value determines which color in the spectrum
shown is the basis, from red to purple. The
saturation level is the amount of hue. In other
words, it is the density of the color. The higher
the saturation, the more of the base color used.
Together the hue and saturation work like
the X and Y coordinates of a number line.
Notice in the figure the target site that is
created on the palette by entering a value for
the hue and saturation below. This technique
chooses a color from the palette.
The luminescence setting is how bright or
dark the color appears. The average color
brightness is 112. If luminescence is set to 0,
the color has no luminescence and is black. If
luminescence is set to 255, the color is white.
Values in between result in varying degrees of
the darkness/lightness of the base color.