尝试使用现有的WordPress功能修改调色板，如：

function my_mce4_options( $init ) {
    $default_colours = \'
        "000000", "Black",
        "993300", "Burnt orange",
        "333300", "Dark olive",
        "003300", "Dark green",
        "003366", "Dark azure",
        "000080", "Navy Blue",
        "333399", "Indigo",
        "333333", "Very dark gray",
        "800000", "Maroon",
        "FF6600", "Orange",
        "808000", "Olive",
        "008000", "Green",
        "008080", "Teal",
        "0000FF", "Blue",
        "666699", "Grayish blue",
        "808080", "Gray",
        "FF0000", "Red",
        "FF9900", "Amber",
        "99CC00", "Yellow green",
        "339966", "Sea green",
        "33CCCC", "Turquoise",
        "3366FF", "Royal blue",
        "800080", "Purple",
        "999999", "Medium gray",
        "FF00FF", "Magenta",
        "FFCC00", "Gold",
        "FFFF00", "Yellow",
        "00FF00", "Lime",
        "00FFFF", "Aqua",
        "00CCFF", "Sky blue",
        "993366", "Brown",
        "C0C0C0", "Silver",
        "FF99CC", "Pink",
        "FFCC99", "Peach",
        "FFFF99", "Light yellow",
        "CCFFCC", "Pale green",
        "CCFFFF", "Pale cyan",
        "99CCFF", "Light sky blue",
        "CC99FF", "Plum",
        "FFFFFF", "White"
        \';
    $custom_colours = \'
        "e14d43", "Color 1 Name",
        "d83131", "Color 2 Name",
        "ed1c24", "Color 3 Name",
        "f99b1c", "Color 4 Name",
        "50b848", "Color 5 Name",
        "00a859", "Color 6 Name",
        "00aae7", "Color 7 Name",
        "282828", "Color 8 Name"
        \';
    $init[\'textcolor_map\'] = \'[\'.$default_colours.\',\'.$custom_colours.\']\';
    $init[\'textcolor_rows\'] = 6; // expand colour grid to 6 rows
    return $init;
}
add_filter(\'tiny_mce_before_init\', \'my_mce4_options\');

这是我用这段代码解决的同一个问题：

<?php

class my_widget extends WP_Widget 
{
    function __construct() 
    {   
        parent::__construct(__CLASS__, __(\'Title\', TEXT_DOMAIN), array ( \'description\' => __( \'Description\', TEXT_DOMAIN ), ) );
    
        //...
        
        add_action( \'admin_enqueue_scripts\', array( $this, \'enqueue_scripts\' ) );
        add_action( \'admin_footer-widgets.php\', array( $this, \'print_widget_scripts\' ), 9999 );
    }

    public function enqueue_scripts( $hook_suffix ) {
        if ( \'widgets.php\' !== $hook_suffix ) {
            return;
        }

        wp_enqueue_style( \'wp-color-picker\' );
        wp_enqueue_script( \'wp-color-picker\' );
        wp_enqueue_script( \'underscore\' );
    }   

    public function print_widget_scripts() {
        ?>
        <script>
            ( function( $ ){
                function initColorPicker( widget ) {
                    widget.find( \'.color-picker\' ).wpColorPicker( {
                        change: _.throttle( function() { // For Customizer
                            $(this).trigger( \'change\' );
                        }, 3000 )
                    });
                }

                function onFormUpdate( event, widget ) {
                    initColorPicker( widget );
                }

                $( document ).on( \'widget-added widget-updated\', onFormUpdate );

                $( document ).ready( function() {
                    $( \'.widget:has(.color-picker)\' ).each( function () {
                        initColorPicker( $( this ) );
                    } );
                } );
                
            }( jQuery ) );
        </script>
        <?php
    }   
}