I want to apply custom CSS on lightning:tab of lightning:tabset I tried using inline CSS, external CSS but there is no luck, I want a way to check below:

(Used to create tab section which is highlighted)

.THIS li:nth-child(2) {
    background-color: dodgerblue !important;
    color: white !important;
    height:1.5rem;
    cursor: no-drop !important;
    pointer-events: none;
    
}
.THIS li:nth-child(7) {
    background-color: dodgerblue !important;
    color: white !important;
    height:1.5rem;
    cursor: no-drop !important;
    pointer-events: none;
}

.THIS li:nth-child(12) {
    background-color: dodgerblue !important;
    color: white !important;
    height:1.5rem;
    cursor: no-drop !important;
    pointer-events: none;
}
.THIS li:nth-child(15) {
    background-color: dodgerblue !important;
    color: white !important;
    height:1.5rem;
    cursor: no-drop !important;
    pointer-events: none;
}

This worked, anyhow I need some other solution as I am getting tabs dynamically there can be "n" number of tabs. and updating the CSS on every tab insertion/deletion is Misery!

Please let me know if anyone has any solution

Many thanks in advance!