<input id="reset_editor" type="submit" class="button" style="background: #7a7a7a; color: #fff; border: none;" value="' . $this->l('Reset') . '" name="reset_editor">

    public function getContent()
    {
        if (Tools::isSubmit('reset_editor')) {
            Configuration::updateValue('primarycolor', '#fff');
        }
......