Why cannot change checkbox color whatever I do?

Question

I try to style checkbox background color, but it won\'t change whatever I do. I am using firefox 29 latest.

Is there some rule changes in css or may be in the browse

Answer 1

Can be very simplified like that :

input[type="checkbox"]{
    outline:2px solid red;
    outline-offset: -2px;
}

Works without any plugin :)