ie10 disabled style not working

I added the following css to make it clear when an option that was available becomes illegal
based on a change in some other selector.

select option[disabled]
{
    background-color: Red !important;
}

So an illegal option has its background color change to red even if it is selected.

This works great in ie7, ie8, ie9. But in ie 10 the selected option does not change
background color. The background color stays white. The red background color
ONLY becomes evident when I select a different valid option.

Does anybody know what I can do to make ie10 behave correctly. I mean even if a selected style tried to override my disabled style the !important; above should prevail. right?"