Radio buttons Output in Theme Customizer

My theme has two color schemes (i.e. two stylesheets – light.css and dark.css) which I would like my multisite users to select via the theme customizer.

I am not able to output the value to my header.php. The code I used to do so is:

<?php if ( get_theme_mod( 'garnish_color_scheme' ) ) { ?>
                    <link rel="stylesheet" href="<?php echo get_template_directory_uri(); ?>/css/<?php echo get_theme_mod( 'garnish_color_scheme' ); ?>" type="text/css" media="screen" />
<?php } else { ?>
                    <link rel="stylesheet" href="<?php echo get_template_directory_uri(); ?>/css/light.css" type="text/css" media="screen" />
<?php } ?>

The code I am using to add the section, setting and control to the customizer is :

/*---------------------------------------------------------------*/
/*	Theme Customizer - Color Scheme
/*----------------------------------------------------------------*/

$wp_customize->add_section('garnish_color_scheme', array(
        'title'    => __('Color Scheme', 'garnish'),
        'priority' => 120,
    ));

$wp_customize->add_setting('garnish_color_scheme', array(
        'default'        => 'value1',
        'capability'     => 'edit_theme_options',
        'type'           => 'option',
    ));

    $wp_customize->add_control('garnish_color_scheme', array(
        'section'    => 'garnish_color_scheme',
        'settings'   => 'garnish_color_scheme',
        'type'       => 'radio',
        'choices'    => array(
            'value1' => 'light.css',
            'value2' => 'dark.css',
        ),
    ));

Any help would be greatly appreciated. Thanks in advance.