If you want to add CSS for your plugin, you can do it with this code in your Javascript file :
$("<style>")
.prop("type", "text/css")
.html("\
#RGBController_colorpicker { display: inline-block; margin-right: 10px; }\
#RGBController_red .ui-slider-range { background-color: #ef2929 !important; }\
")
.appendTo("head");
much more elegant than with jQuery.css, and it handles “!important”.