how to exclude elements with any attached class in jquery


Does anyone know how i'd exclude elements from a selection if they have any class whatsoever explicitly attached to them?

Here i'm selecting all columns within the 'tdhead' element, but want to exclude anything I have there that's making use of another class, for example I might have a breadcrumb or toolbar as a single column across the top, in the tdhead.

_create: function () {
var self = this.element;
var headerColumns = self.children("thead").children("tr").children("td").not(".");

headerColumns.css("background-color", "Red");

So what's not working is the .not(".") part - whats the correct way to select (or not select) anything with any class?