Color

Web DesignProfessor Frank

Color Displays

• Based on cathode ray tubes (CRTs) or back-lighted flat-screen

• Monitors transmit light - displays use the red-green-blue (RGB) additive color model

Color Displays

Pixels

• Display screen = grid of x and y coordinates• Each box = 1 pixel• Pixel = picture element

Pixels and Color Depth

• Video RAM/VRAM – OS memory dedicated to screen display

• 1 single bit of memory per pixel

Black & White Display

8 Bit / 256 Color Display

• More memory/pixel = more colors to display• 8bits of memory/pixel = 256 colors

“True Color”

• True color – 24 bits memory per pixel (8 red, 8 green, 8 blue)

Color Depth & Graphics Files

• 8-bit, or 256-color, image files (uncompressed) dedicate 8 bits to each color pixel in the image

• In 8-bit images the 256 colors that make up the image are stored in an array called a "palette" or an "index"

True Color / 24 Bit Images

Color Terminology

• Hue - wavelength of color along the spectrum of visible light, ie “yellow,” “orange,” or “red.”

• Saturation - the intensity of a color• Brightness - The lightness or darkness of a

color or how close to either black or white a given color is.

Color Terminology