You can describe color on the screen in a variety of ways, but most of these descriptions are just different ways of telling the computer how much red, green, and blue are in a particular color. Browser-safe Colors? Certain colors always display properly on any monitor. These colors are called browser-safe colors. You’ll find them fairly easy to remember because their values stay consistent. In hexadecimal values, you can use any combination of 00, 33, 66, 99, CC, and FF. In numeric values, use 0, 51, 102, 153, 204, or 255. In percentages, use 0, 20, 40, 60, 80, or 100. The behavior of each percentage value depends on the property in use. URLs A Uniform Resource Locator (URL) is the unique address of something on the Web. This resource could be an HTML document, a graphic, a CSS file, a JavaScript file, a sound or video file, a CGI script, or any of a variety of other file types. URLs can be local—describing the location of the resource relative to the current document— or global—describing the absolute location of the resource on the Web and beginning with http://.