You are talking about filtering the content. This would not be easy to add. You’d need to create a new filter for “the_content”, then you’d need to parse all the HTML, find the parts that you want to change and alter them.
The other choice is to add custom CSS using the “get_header” hook
add_action('get_header', 'my_custom_page_css');
function my_custom_page_css() {
// we need to get the post ID because this is outside the loop
$queried_object = get_queried_object();
if (!isset($queried_object->ID)) {
// not a post
return;
}
$post_id = $queried_object->ID;
?>
<style type="text/css">
h1 {
color: <?php the_field('heading_color', $post_id);
}
</style>
<?php
}
I know this is an old topic so hopefully this helps someone.
