jquery/jquery-mobile — pull request #5033 by MauriceG (2012-09-19 12:06:17+00:00)
Title: Select: Add optgroup theming for non-native selects - Fix for #4809: optgroup element is not themed

Demo: http://jsfiddle.net/MauriceG/ULZfw/show/light/
Edit: http://jsfiddle.net/MauriceG/ULZfw/