Change CSS Styles BurguerMenu NavBar - css

Question

I have a Bootstrap Navbar and I want that when I click on deploy button, this CSS (of the button) changes (I do not like CSS Button default). So... I want next:
When I click on Menu (in Xtra Small Sizes -as movile-) its CSS Styles change (eg: background-color: red).
How could I do this? What is his ClassNameCss? (eg: .navbar button[aria-expanded=true]) Thank you.
EDIT: Added my NavBar Code:
<nav class="navbar navbar-default" role="navigation">
<div class="navbar-header">
<button type="button" class="navbar-toggle navbar-collapse-left" data-toggle="collapse" data-target=".navbar-collapse">
<span class="sr-only">Menú</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
{/*<a class="navbar-brand" href="/inicio"><img id="idFotoLogotipo" width="200px" src="./assets/images/cabecera_CE.jpg"/></a>*/}
<a class="navbar-brand visible-xs-block" /*href="http://www.upct.es/"*/><span id="idTextoLogotipo">- INCIDENCIAS -</span></a>
</div>
<div class="collapse navbar-collapse">
<ul class="nav navbar-nav navbar-left">
<MenuNavItem to='/administrador/inicio' index={true} /*menuItemActive="inicio"*/>Inicio</MenuNavItem>
<MenuNavItem to='/administrador/nueva_incidencia' /*menuItemActive="nueva_incidencia"*/>Nueva Incidencia</MenuNavItem>
<MenuNavItem to='/administrador/incidencias_recibidas' /*menuItemActive="incidencias_recibidas"*/>Incidencias Recibidas</MenuNavItem>
<MenuNavItem to='/administrador/informes' /*menuItemActive="informes"*/>Informes</MenuNavItem>
</ul>
<ul class="nav navbar-nav navbar-right">
<li class="divider visible-xs-block"></li>
{this.state.logged === true ? <p class="nav navbar-text hidden-xs"><span class="glyphicon glyphicon-user"></span> Bienvenido, {this.state.nombre} ({this.state.dni})</p> : ''}
{this.state.logged === true ? <p class="nav navbar-text visible-xs-block"><span class="glyphicon glyphicon-user"></span> Bienvenido, {this.state.nombre}</p> : ''}
{this.state.logged === true ? <li class="salir"><span class="glyphicon glyphicon-off"></span> Salir</li> : <li class="entrar"><span class="glyphicon glyphicon-user"></span> Entrar</li>}
</ul>
</div>
</nav>

Answer 1

If you mean the 'burger menu' (three lines) dropdown toggle button shown here:
Then you should be able to target this with:
.navbar-toggle[aria-expanded="true"],
.navbar-toggle[aria-expanded="true"]:focus {
background-color: red;
}
Note that the :focus style is required as otherwise the default grey background colour will still show when the button is clicked, as at that point the button will have focus.
EDIT: try this example - I've since prefixed the styles with .navbar-default, which should ensure the styles work.
.navbar-default .navbar-toggle[aria-expanded="true"],
.navbar-default .navbar-toggle[aria-expanded="true"]:focus {
background-color: red;
}
.navbar-default .navbar-collapse[aria-expanded="true"] {
background-color: #428bca;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<nav class="navbar navbar-default">
<div class="container-fluid">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="#">Brand</a>
</div>
<!-- Collect the nav links, forms, and other content for toggling -->
<div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
<ul class="nav navbar-nav">
<li class="active">Link <span class="sr-only">(current)</span></li>
<li>Link</li>
<li class="dropdown">
Dropdown <span class="caret"></span>
<ul class="dropdown-menu">
<li>Action</li>
<li>Another action</li>
<li>Something else here</li>
<li role="separator" class="divider"></li>
<li>Separated link</li>
<li role="separator" class="divider"></li>
<li>One more separated link</li>
</ul>
</li>
</ul>
<form class="navbar-form navbar-left">
<div class="form-group">
<input type="text" class="form-control" placeholder="Search">
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
<ul class="nav navbar-nav navbar-right">
<li>Link</li>
<li class="dropdown">
Dropdown <span class="caret"></span>
<ul class="dropdown-menu">
<li>Action</li>
<li>Another action</li>
<li>Something else here</li>
<li role="separator" class="divider"></li>
<li>Separated link</li>
</ul>
</li>
</ul>
</div><!-- /.navbar-collapse -->
</div><!-- /.container-fluid -->
</nav>