Some Slight Code Help?

Hey, I'm just beginning to code some CSS for my den and profile page, starting with my den. But I've seem to have run into a bit of a hiccup? I'm currently trying to change the color of the large black navigation bar up top and the dark blue "Welcome back," status bar using the code below, but so far I see no changes using Stylus' live preview feature. Is there something wrong with my code?

.navbar-main {
    background-color: #283d37;
}
.navbar-status {
    background-color: #b1b1a2;
}