function custom_theme_change_custom_theme() {
    global $top_bar_color;
    $top_bar_color = '#2b3643';
    if (strpos($_SERVER['HTTP_HOST'], 'example.com') !== false) {
        switch (returnRoleForTheme()) {
            case 'old': $th = 'theme_1'; $top_bar_color = '#2b3643'; break;
            case 'young': $th = 'theme_2'; $top_bar_color = '#6dad19'; break;
            case 'kid': $th = 'theme_3'; $top_bar_color = '#6dad19'; break;
        }
    }
    return $th;
}