Adobe 23101335 User Guide - Page 119

109 Chapter 3: Working with Color F amiliarity with color theory and terminology can help you understand how color is measured and how Adobe Photoshop and Adobe ImageReady use this information to define, display, and print color values. After you determine the appropriate color mode for your image, you can apply colors and make color and tonal adjustments. About color modes and models (Photoshop) A color mode determines the color model used to display and print images. Photoshop bases its color modes on established models for describing and reproducing color. Common models include HSB (hue, saturation, brightness); RGB (red, green, blue); CMYK (cyan, magenta, yellow, black); and CIE L*a*b*. Photoshop also includes modes for specialized color output such as Indexed Color and Duotone. ImageReady uses RGB mode to work with images. In addition to determining the number of colors that can be displayed in an image, color modes affect the number of channels and the file size of an image. You can set up the Info palette so that you can select any tool, position the pointer over any part of an image, and determine the color value under the pointer. You can customize the Info palette and color samplers to express color values using HSB, RGB, CMYK, Lab, or Grayscale modes without changing the mode of the image itself. (See the procedure to change Info palette options in "Using the Info palette" on page 63.) For more information, see "Seeing the color values of pixels (Photoshop)" in online Help. HSB model Based on the human perception of color, the HSB model describes three fundamental characteristics of color: • Hue is the color reflected from or transmitted through an object. It is measured as a location on the standard color wheel, expressed as a degree between 0° and 360°. In common use, hue is identified by the name of the color such as red, orange, or green.