Function: color-name-to-rgb

Convert COLOR string to a list of normalized RGB components.
COLOR should be a color name (e.g. "white") or an RGB triplet
string (e.g. "#ff12ec").

Normally the return value is a list of three floating-point
numbers, (RED GREEN BLUE), each between 0.0 and 1.0 inclusive.

Optional argument FRAME specifies the frame where the color is to be
displayed. If FRAME is omitted or nil, use the selected frame.
If FRAME cannot display COLOR, return nil. (fn COLOR &optional FRAME)