takes strings of colour values, like hex, rgba etc as would be used in web
$.colour.fill
Examples
$.use(update);
function update() {
$.colour.fill="red";
$.shape.rectangle($.w/2,$.h/2,$.w,$.h);
$.colour.fill="#e3e3e3";
$.shape.rectangle($.w/2,$.h/2,100,100);
$.colour.fill="rgba(0,0,0,0.5)";
$.shape.rectangle(30,30,50,50);
}