mui.DoMethod(id, "SetColor", startx, starty, stopx, stopy, color)
Startx, starty, stopx, and stopy can either be absolute coordinates or one of the following special values:
From the Hollywood script the color is specified as a simple numerical value containing 8 bits for each component. When you specify the color in the XML file, it has to be passed as a 6 character string prefixed by the #-character (just like in HTML).
To change the color that should be used for newly text, use the Texteditor.Color attribute instead.