Add colours to ACF colour picker

acf-gutenberg-blocks.php

function themeprefix_acf_input_admin_footer() {

    ?>
    <script type="text/javascript">
        (function($) {

            acf.add_filter('color_picker_args', function( args, $field ){

// add the hexadecimal codes here for the colors you want to appear as swatches
                args.palettes = ['#F0F4F9', '#FFFBC5']

// return colors
                return args;

            });

        })(jQuery);
    </script>
    <?php

}

add_action('acf/input/admin_footer', 'themeprefix_acf_input_admin_footer');