How can i modify the navbar

How can i modify the navbar, for example i want to change the color but i don’t find the side where modify it.

Including this code will help you.
.navbar-default .navbar-nav > li > a:hover, .navbar-default .navbar-nav > li > a:focus {
color: #a3159a;
}

Better to create a custom app and connect with hook.

thanks for your answer, it was usefull