You may want to read the following topic. Your display type and the Number of Colors selection determine the number of colors buttons that make up a palette. To keep the number of colors used on a high-color display to a minimum, Number of Colors is set to More Colors for Applications by default. To increase the number of color buttons on a high-color display, select More Colors for Desktop in the Number of Colors To Use dialog box and restart the current session. While you can't use more colors than your display allows, you can reduce the amount of colors used by the Desktop by specifying a lower-value color usage. For example, if you have a high-color display and have selected More Colors for Desktop in the Number of Colors To Use dialog box, but you want to run a color-rich application such as a CAD program, you should choose More Colors for Applications or Most Colors for Applications to decrease the number of colors the desktop uses. The remaining colors are available for the CAD program.