Trouble getting file url of file attachment in cloneable group

Hi There I have another follow up to this.

For the special colors fields I made I had to make an option for dual color using a conditional selection box like this:

add_filter( 'rwmb_meta_boxes', 'prefix_register_special_colours' );
function prefix_register_special_colours( $meta_boxes ) {
    $meta_boxes[] = array(
        'id' => 'Special_Colours',
        'title' => esc_html__( 'Special Order Colours' ),
        'post_types' => array( 'product' ),
        'context' => 'advanced',
        'priority' => 'default',
        'autosave' => 'true',
        'fields' => array(
            array(
                'id'   => 'has_special_colours',
                'name' => 'Special Order Colours',
                'desc'  => 'Select if this product has special order colours',
                'type' => 'checkbox',
                'std'  => 0,
            ),
            array(
                'id' => 'special_colours',
                'type' => 'group',
                'group_title' => 'Colour {#}',
                'collapsible' => true,
                'save_state' => false,
                'clone'  => true,
                'sort_clone' => true,
                'hidden' => array( 'has_special_colours', '!=', '1' ),
                'fields' => array(
                    array(
                        'id'   => 'colour_name',
                        'type' => 'text',
                        'name' => 'Colour Name',
                    ),
                    array(
                        'id' => 'special_colour',
                        'type' => 'color',
                        'name' => esc_html__( 'Special Colour' ),
                        'desc' => esc_html__( 'Select a colour to appear on the product page as a special order colour' ),
                    ),
                    array(
                        'id'    => 'is_dual',
                        'name'  => 'Is Dual Colour?',
                        'desc'  => 'Pick if dual colour',
                        'type'  => 'select',
                        'options' => array(
                            'No'         => 'No',
                            'Yes'        => 'Yes',
                        ),
                    ),
                    
                    array(
                        'id' => 'special_colour2',
                        'type' => 'color',
                        'hidden' => array( 'is_dual', '!=', 'Yes' ),
                        'name' => esc_html__( 'Special Colour2' ),
                        'desc' => esc_html__( 'Select a colour to appear on the product page as a special order dual colour' ),
                    ),
                ),
            ),
        ),
    );
    return $meta_boxes;
}

and to display it I am using this:

add_action( 'woocommerce_before_add_to_cart_button', 'product_special_colours', 5 );
function product_special_colours() {
    $has_special_colours = rwmb_meta( 'has_special_colours' );
    $special_colours = rwmb_meta( 'special_colours' );
    if ( ! empty( $special_colours ) ) {
        echo '<table class="variations" cellspacing="0">
            <tbody>
                <tr>
                    <td class="label">
                        <label for="so_color">Special Order Colours</label>
                    </td>
                    <td class="value woo-variation-items-wrapper">
                        <ul class="variable-items-wrapper color-variable-wrapper">';
                            foreach ( $special_colours as $special_colour ) {
                                $is_dual = isset ( $special_colour['is_dual'] ) ? $special_colour['is_dual'] : '';
                                if ($is_dual != "Yes") {
                                    $colour_name = isset( $special_colour['colour_name'] ) ? $special_colour['colour_name'] : '';
                                    if ( isset( $special_colour['special_colour'] ) ) {
                                        $colour = isset( $special_colour['special_colour'] ) ? $special_colour['special_colour'] : '';
                                        echo '<li class="special_colour" style="background-color: ' . $colour . ' ">
                                            <span class="tooltip">' . $colour_name . '</span>
                                        </li>';
                                    }
                                }
                                else {
                                    $colour_name = isset( $special_colour['colour_name'] ) ? $special_colour['colour_name'] : '';
                                    if ( isset( $special_colour['special_colour'] ) ) {
                                        $colour = isset( $special_colour['special_colour'] ) ? $special_colour['special_colour'] : '';
                                        $colour2 = isset( $special_colour['special_colour2'] ) ? $special_colour['special_colour2'] : '';
                                        echo '<li class="special_colour" style="background: linear-gradient(-45deg, ' . $colour . ' 0%, ' . $colour . ' 50%, ' . $colour2 . ' 50%, ' . $colour2 . ' 100%);">
                                            <span class="tooltip">' . $colour_name . '</span>
                                        </li>';
                                    }
                                }
                            }
                        echo '</ul>
                    </td>
                    <td>
                        <p>To order one of our special special order colours please <a href="/contact/">contact us</a>. <br> Please note that shipping of special orders can take up to 12 weeks.</p>
                    </td>
                </tr>
            </tbody>
        </table>';

    } 
}

When I use the selection to choose whether the color is dual color or not it works perfect, the issue is when I delete information from all the fields if I want to display no special colors on the frontend, when the product is saved the selection field defualts to the first option "no" so the stuff displays on the frontend since it can't pass if ( ! empty( $special_colours ) ) {

You can see I setup a conditional checkbox on whether or not to show the fields, and when I run if ( ! empty( $has_special_colours ) ) { it works. I'm thinking that I can also just use a checkbox instead of a select field for "is_dual" selector since I think an empty checkbox will register as empty, but there may be a case when I want to use a select box with multiple selections. I'm just wondering what is the best solution here, since I feel that cleaning out all the fields and only displaying when there is stuff in the fields is the cleanest option.

This also leads me to ask, if I were to remove all the code that registers the fields, what happens to the data? What happens to the data when I change the id name of a field? It is still around under the old id? How to I clean out the data if I want to remove fields or change and id? If there is any documentation on this that would be great,

Thanks again for all your help,

Steve

ok thanks for the information, do you have a suggestion on the best way to not show any of the color stuff when there is no information? In the fields? I there a way to set a select field as empty?

Steve

Ok thank you very much for your advice!

Steve