[Resolved] Body Class for Pages & Posts Including An ACF Field

Hello,

I am trying to include an acf field into my body class function for posts (which is working well) and my php is failing to do this. What I have originally works for single posts:

add_filter('body_class','add_category_to_single');
   function add_category_to_single($classes) {
     if (is_single() ) {
       global $post;
 
       foreach((get_the_category($post->ID)) as $category

) {
             $classes[] = $category->category_nicename;
       }
 
     }
    
     return $classes;
 }

If I add the acf field (checkbox for picking a colour to add to the body class) called ‘border_page_colour’ so that the acf field adds a colour class to the body for pages, it fails. i.e no class is set. The code I’m using is:

add_filter('body_class','add_category_to_single');

   $value = get_field('border_page_colour'); // The ACF Field

   function add_category_to_single($classes) {
     if (is_singular() ) {
       global $post;
 
       foreach((get_the_category($post->ID)) as $category) {
             $classes[] = $category->category_nicename . $value;
       }
 
     }
     elseif ( is_page() ) {
        $classes[] = $value; // Supposed to take the ACF Field Value
     }
    
     return $classes;
 }