Meta Box

Hi Long!
That works great! Many thanks!
Last question:
Could this also be implemented with the code I found here: https://metabox.io/wordpress-style-posts-in-particular-category/

Code:

<div>

function estar_child_output_frontend() {
    If ( ! is_single() ) {
        return;
    }
    $categories       = get_the_category();
    $background_color = get_term_meta( $categories[0]->term_id, 'background_color_taxonomy', true );
    if ( ! $background_color ) {
        return;
    }
    echo '<style>
        .single-post {
            background-color: ' . $background_color . ';
        }
    </style>';
}
add_action( 'wp_head', 'estar_child_output_frontend' );

</div>

If yes, how should I implement it?

Hi Long, Thanks for your reply. I changed those 2 line code but it doen't work
the <style> doesn't get to the front end.
As I said it worked with WP categories but \it doesn't work with custom taxonomy.

This is the custom taxonomy I've made:

<div>
<?php
add_action( 'init', 'your_prefix_register_taxonomy' );
function your_prefix_register_taxonomy() {
    $labels = [
        'name'                       => esc_html__( 'post style color', 'your-textdomain' ),
        'singular_name'              => esc_html__( 'post style color', 'your-textdomain' ),
        'menu_name'                  => esc_html__( 'Post style color', 'your-textdomain' ),
        'search_items'               => esc_html__( 'Search post style color', 'your-textdomain' ),
        'popular_items'              => esc_html__( 'Popular post style color', 'your-textdomain' ),
        'all_items'                  => esc_html__( 'All post style color', 'your-textdomain' ),
        'parent_item'                => esc_html__( 'Parent post style color', 'your-textdomain' ),
        'parent_item_colon'          => esc_html__( 'Parent post style color', 'your-textdomain' ),
        'edit_item'                  => esc_html__( 'Edit post style color', 'your-textdomain' ),
        'view_item'                  => esc_html__( 'View post style color', 'your-textdomain' ),
        'update_item'                => esc_html__( 'Update post style color', 'your-textdomain' ),
        'add_new_item'               => esc_html__( 'Add new post style color', 'your-textdomain' ),
        'new_item_name'              => esc_html__( 'New post style color name', 'your-textdomain' ),
        'separate_items_with_commas' => esc_html__( 'Separate post style color with commas', 'your-textdomain' ),
        'add_or_remove_items'        => esc_html__( 'Add or remove post style color', 'your-textdomain' ),
        'choose_from_most_used'      => esc_html__( 'Choose most used post style color', 'your-textdomain' ),
        'not_found'                  => esc_html__( 'No post style color found', 'your-textdomain' ),
        'no_terms'                   => esc_html__( 'No post style color', 'your-textdomain' ),
        'filter_by_item'             => esc_html__( 'Filter by post style color', 'your-textdomain' ),
        'items_list_navigation'      => esc_html__( 'Post style color list pagination', 'your-textdomain' ),
        'items_list'                 => esc_html__( 'Post style color list', 'your-textdomain' ),
        'most_used'                  => esc_html__( 'Most Used', 'your-textdomain' ),
        'back_to_items'              => esc_html__( 'Back to post style color', 'your-textdomain' ),
    ];
    $args = [
        'label'              => esc_html__( 'Post style color', 'your-textdomain' ),
        'labels'             => $labels,
        'description'        => '',
        'public'             => true,
        'publicly_queryable' => true,
        'hierarchical'       => true,
        'show_ui'            => true,
        'show_in_menu'       => true,
        'show_in_nav_menus'  => false,
        'show_in_rest'       => true,
        'show_tagcloud'      => false,
        'show_in_quick_edit' => true,
        'show_admin_column'  => false,
        'query_var'          => true,
        'sort'               => false,
        'meta_box_cb'        => 'post_tags_meta_box',
        'rest_base'          => '',
        'rewrite'            => [
            'with_front'   => false,
            'hierarchical' => false,
        ],
    ];
    register_taxonomy( 'post-style-color', ['post'], $args );
}
</div>

This is the custom fields I made:

'<div>
<?php
add_filter( 'rwmb_meta_boxes', 'your_prefix_function_name' );

function your_prefix_function_name( $meta_boxes ) {
    $prefix = '';

$meta_boxes[] = [
    'title'      => __( 'Color style Taxonomy', 'your-text-domain' ),
    'id'         => 'color-style-taxonomy',
    'taxonomies' => ['post-style-color', 'category'],
    'fields'     => [
        [
            'name'    => __( 'Background Color', 'your-text-domain' ),
            'id'      => $prefix . 'background_color_taxonomy',
            'type'    => 'color',
            'columns' => 3,
        ],
    ],
];

return $meta_boxes;
}
</div>'

This is the dode I put in the fuctions.php:

<div>
// MetaBox color style taxonomy
function astr_child_output_frontend() {
    If ( ! is_single() ) {
        return;
    }
    $term_id = get_queried_object_id();
$background_color = rwmb_meta( 'background_color_taxonomy', ['object_type' => 'term'], $term_id );
    if ( ! $background_color ) {
        return;
    }
    echo '
<!-- custom style taxonomy -->
    <style>
        .single-post {
            --bg-color1: ' . $background_color . ';

    }
</style>';
}
add_action( 'wp_head', 'astr_child_output_frontend' );

</div>

Do you know why it doesn't work?

Hello,
I don't want to make a setting page. I want to be able to set colors for every posts that is why I displayed the custom fields in the post section.

I wanted to use it with elementor but your extension doesn't work with it, and you didi find yet a solution, here is the post about it:
https://support.metabox.io/topic/color-picker-doesnt-seem-to-work/?fbclid=IwAR2AC8byNLXJ3eJMKLO9QS2lQTqJUIv40-CWJYs5spqIGtQ7Sx_AqV_vJk4

Can you please help me? How can I make this code work:
<div>
--background-color: <?php
$background_color = rwmb_meta( //Change the variable to your desired varible name
'background_color_picker', //Color Picker ID
['object_type' => 'Post'],
'post' ); //Option Name from Settings Page
echo $background_color;
?>;
</div>

What should I change in it to make it display the color picker values in the CSS?