body > div > div > div.navbar.navbar-inverse > div > div.navbar-header > button > span:nth-child(2) {
    background-color: #000 !important;
}
span.icon-bar:nth-child(3){
    background-color: #000 !important;
}

span.icon-bar:nth-child(4){
    background-color: #000 !important;
}
.navbar-inverse .navbar-toggle:hover, .navbar-inverse .navbar-toggle:focus {
    background-color: #fff !important;
}