Dynamic Stylesheet with Redux framework

I have fall a problem to make stylesheet dynamic by redux. In my config.php I have write this code.

array(
    'id'        => 'scheme',
    'type'      => 'select',
    'title'     => __('Theme Stylesheet', 'redux-framework-demo'),
    'subtitle'  => __('Select a predefined color scheme. They`re located in `/css/color-schemes/` theme folder', 'redux-framework-demo'),
    'options'   => array('orange.css' => 'orange.css', 'red.css' => 'red.css', 'blue.css' => 'blue.css'),
    'default'   => 'orange.css',
),

and I have tried to enqueue stylesheet by writting bellow code on functions.php

if(!isset($redux_demo['scheme'])) {
    wp_enqueue_style( 'pm-color-scheme', get_stylesheet_directory_uri() . '/css/color-schemes/orange.css' );
}
else {
    wp_enqueue_style( 'pm-color-scheme', get_stylesheet_directory_uri() . '/css/color-schemes/'.$redux_demo['scheme'] );
}

But when I select blue.css from theme option like this http://prntscr.com/3s5td0

I get default value that is orange.css everytime like this http://prntscr.com/3s5ucm.

what can I do now?