Dash Bootstrap Table CSS properties

I’m trying to alter the color of the header bottom-border of the dash bootstrap table component (Table - dbc docs). Specifically, when adding a dbc.Table to my dashboard, I’d like to change the color of the thick black bottom border in the header row. My CSS attempts haven’t worked. Hoping someone has an idea!

.table > :not(:first-child) {
  border-top: 2px solid red; //May need to use !important

This worked for me once and changed the color of the thick line between the table head and body from black to red, but does not seem to work for older versions of Dash.

Thanks! Love it