Hi Patrick,
As far as I know, you can’t use more than 1 filter for an item, because if you do so, only the first one is applied and the next one is ignored. But if I’ve understood you correctly for the effect you want to achieve, just add a “have a colour” filter for each coloured item and a “white” filter for your white items. Unfortunately, set in that way, you won’t be able to filter the items by individual colour.