HEX to RGB
The colour space is theoretically an unbounded extrapolation of sRGB similar to scRGB because gamut can be determined in Cascading Style Sheets by making one or more of the red, green, and blue components negative or more than 100%.  This method of non-sRGB colour specification needs the RGB() function call. Because of the hexadecimal syntax, it is not possible (and thus impossible in legacy HTML documents that do not use CSS).
Due to the fact that both Mosaic and Netscape Navigator were initially X Window System applications, their first colour lists were based on the X11 colour names. The colorimetric definition for web colours, known as sRGB, is clear-cut and connects the chromaticities of a certain phosphor set, a specific transfer curve, an adaptive whitepoint, and viewing conditions.  When these