The desired color is specified with a value whose string value must have one of the following forms:
- Any of the valid textual names for a color defined in the server's color database file, such as red or PeachPuff.
- A numeric specification of the red, green, and blue intensities to use to display the color. Each R, G, or B represents a single hexadecimal digit. The four forms permit colors to be specified with 4-bit, 8-bit, 12-bit or 16-bit values. When fewer than 16 bits are provided for each color, they represent the most significant bits of the color, while the lower unfilled bits will be repeatedly replicated from the available higher bits. For example, #3a7 is the same as #3333aaaa7777.