I'm trying to change the background color of Active tab in Apex 18.2
Current:

Required

I have tried below, but not working
.t-Header-nav-list .a-MenuBar-item.a-Menu--current.is-focused {
border-bottom: 2px solid blue;
background-color : blue;
}
.t-Header .a-MenuBar-item.a-Menu--current, .t-Header .a-MenuBar-item.a-Menu--current.is-focused {
border-bottom: 2px solid blue;
background-color : blue;
}