Specifications

Crestron Programming Design Kit
Doc. 5277J | crestron.com
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Appendix C: Color Theory
The following color definitions may be useful when considering interface design.
• 8-bit color allocates 8 bits (1 byte) of memory to each pixel, up to 256 different colors.
• 16-bit color allocates 16 bits (2 bytes) of memory to each pixel, producing 65,536 colors.
• 24-bit color uses 24 bits (3 bytes) of memory per pixel in a color image, up to 16,777,216 colors can be
represented in the color palette.
• True color is 32-bit color. The extra byte, called the alpha channel, is used for control and special effects
information (for example, transparency).
Colors can appear in nearly infinite variation, which can make selecting appropriate colors for the project difficult.
This guide attempts to simplify the choices by presenting a few basic principles of color theory.
There are three basic (primary) video colors, red, green, and blue. All other colors are derived from these three.
Mixing two of the primary colors creates the secondary colors. Red plus green = yellow, Blue plus red = magenta,
and blue plus green = cyan.
Light versus Paint
Touch screens use Red, Green, and Blue as their primary colors. The screen emits light made up of thousands of
tiny red, green, and blue pixels that are so close together it is not easily to distinguish an individual light emitter.
By turning these lights on and off, the illusion of mixed colors is reproduced. In the case of a touch screens, black
is the absence of all light (all light emitters off) and white is the presence of all light (all red, green and blue light
emitters on full).
The painter’s palette operates on a different principle. The white surface of a paper or canvas reflects all available
light and appears white. Adding colors to the white background decreases the amount of light by absorbing specific
frequencies of light. For example, red absorbs the green and blue light. What we see is the light reflected from the
surface to our eyes. For paints, the absence of all paint is the white surface, and the presence of all colors is black,
absorbing all light.
It is important to keep in mind that when designing a touch screen the surface is painted with light.