.app-topbar{
    background-color: #fff;
    border-bottom: 1px solid rgba(0,0,0,.08);
    color: #7FB3FF; /* azzurro pastello */
}

.app-topbar a,
.app-topbar .nav-link{
    color: #7FB3FF;
}

.app-topbar a:hover,
.app-topbar .nav-link:hover{
    color: #4D8FE6; /* un filo più deciso in hover */
}