HTML Option menu border override without making custom element?

Question

What are the css selectors used to style the border of the option menus like shown here. I want to override the default styles and not make a custom menu by hiding the default one like how its is done here How to style the <option> with only CSS?.

I am trying to change the border color. and styling the option tags like this doesn't do it

option {
    border-color: black;
}