In some of my pull down boxes I have 'read only' attributes.

I'd like to make these a different colour and size than the other selectable option values.

Is this possible?

I can style the option as a whole with something like
#attrib-10{
font-size: 1.5em;
}

And I note from firefox that the element has value = 10

but i'm not sure how to instruct the stylesheet.

Any help appreciated.