ActionScript for Flash MX: The Definitive Guide, 2nd Edition By Colin Moock
Chapter 18. ActionScript Language Reference
capabilities.screenColor Property
Flash 6
the color mode supported by the screen (color, grayscale, or black and white)
read/write
System.capabilities.screenColor
Description
The string screenColor property indicates the color mode supported by the device on which the Flash Player is running. It allows movies with subtle color differences to switch to a high-contrast color scheme when played on a grayscale or black and white system. Possible values are: "color" (supports more than two colors), "gray" (grayscale), and "bw" (black and white or 2-color display).
The corresponding server string for screenColor is COL, with possible values of "color", "gray", and "bw". See capabilities.serverString for details.