Color in different programming languages is usually represented by a red, green and blue component. The final color is a combination of the three primary colors of light. Typically, values are used ranging from 0 to 255 for each of the components, however, some systems will want you to enter a hexadecimal number in the form RRGGBB where RR is the red value expressed as hexadecimal, GG is the green value, and BB is the blue value. Other systems, such as Java, will want an integer where bits 0-7 are the red value, 8-15 the green, and 16-23 the blue.
This page will let you enter in RGB values, and by pressing evaluate, see the correspinding hexadecimal and integer representations of the color. The background of the page will change to the color selected.