Color strings are used in the following functions:
Xlib supports the use of abstract color names, for example, red or blue. A value for this abstract name is obtained by searching one or more color name databases. Xlib first searches zero or more client-side databases; the number, location, and content of these databases is implementation dependent and might depend on the current locale. If the name is not found, Xlib then looks for the color in the X server's database. If the color name is not in the Host Portable Character Encoding the result is implementation dependent.
A numerical color specification consists of a color space name and a set of values in the following syntax:
<color_space_name>:<value>/.../<value>
The following are examples of valid color strings.
"CIEXYZ:0.3227/0.28133/0.2493"
"RGBi:1.0/0.0/0.0"
"rgb:00/ff/00"
"CIELuv:50.0/0.0/0.0"
The syntax and semantics of numerical specifications are given for each standard color space in the following sections.