How to add a button to ACF tiny MCE editor

How to add a button to the ACF WYSIWYG editor (for example "text color" button). I tried this code but it doesn't work :(

add_filter( 'acf/fields/wysiwyg/toolbars' , 'dw_add_buttons_to_acf_wysiwyg_editor'  );
function dw_add_buttons_to_acf_wysiwyg_editor( $toolbars ){
    $toolbars['Full'][2][] = 'forecolor';

    return $toolbars;
}