Where is CSS for jQuery UI's .ui-selected Defined?

Question

I'm trying to apply jQuery UI Selectable to a portion of my website. However, I do not see either the selection box while dragging the mouse, nor does the color of selected li elements change.

So to understand the problem, I went back to the source:

http://jqueryui.com/demos/selectable/

I see (using IE9 developer tools) that a style .ui-selected is applied to selected elements. Using Trace Styles, IE shows that background-color is originally defined in jquery-ui.css but overridden (ultimately) by #selectable .ui-selected. However, IE does not show the source of #selectable .ui-selected. Searching the jQuery UI style sheet I reference, jquery-ui-1.8.18.custom.css, finds no mention of ui-selected, nor do I find it in jquery.ui.selectable.css.

Where exactly is the demo page getting the CSS for the background color?

Answer 1

I found one of the other jQueryUI demos defines the style for those classes in a custom style sheet, so I ended up following that lead.

http://jqueryui.com/demos/selectable/#serialize

It seems odd that those styles are not part of jQueryUI Themeroller. Perhaps that will change in the future.