You would have to overwrite the CSS rule:
.navbar-inverse .brand, .navbar-inverse .nav > li > a
or
.navbar .brand, .navbar .nav > li > a
depending if you are using the dark or light theme, respectively. To do this, add a CSS with your overwritten rules and make sure it comes in your HTML after the Bootstrap CSS. For example:
.navbar .brand, .navbar .nav > li > a {
color: #D64848;
}
.navbar .brand, .navbar .nav > li > a:hover {
color: #F56E6E;
}
There is also the alternative where you customize your own Boostrap here. In this case, in the Navbar section, you have the @navbarLinkColor
.