As others have also mentioned, this can be readily solved by adding the following to the onCreate() of the Activity:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS);
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
getWindow().setStatusBarColor(ContextCompat.getColor(this, R.color.primary_dark));
}
However, the important point I want to add here is that in some cases, even the above does not change the status bar color. For example, when using MikePenz library for Navigation Drawer, it implicityly overrides the status bar color, so that you need to manually add the following for it to work:
.withStatusBarColorRes(R.color.status_bar_color)