1. A method of defining colors for a graphical user interface having a plurality of interface elements each having visual attributes, comprising: providing a color palette list that includes a plurality of variable strings each of which has assigned thereto a color value; providing a style sheet specifying color attributes of at least some of the interface elements, at least one of the color attributes of at least one of the interface elements being specified by reference to one of the variable strings; and generating the user interface with the at least some interface elements having colors in accordance with the specified color attributes.