A WordPress utility to handle term meta easily.
composer require kunoichi/term-meta
In your theme's functions.php:
if ( class_exists( 'Kunoichi\TermMeta\ColorMeta' ) ) {
new Kunoichi\TermMeta\ColorMeta( 'category_color', 'category', [
'label' => __( 'Color', 'your-domain' ),
'admin_column' => true,
] );
}
To get this color, use WordPress builtin function get_term_meta( $term_id, $meta_key, $single ) .
<?php
// For example, display category title
// with specified background color
// in category archive.
$color = get_term_meta( get_queried_object_id(), 'category_color', true ) ?: '#000';
?>
<h1 style="background-color: <?php echo esc_attr( $color ) ?>">
<?php the_archive_title(); ?>
</h1>