All unlabelled items are rejected by Smart Folder rule to reject one label

Description

I use a green label to distinguish rated items for my charity work - which I want to display separately to my other jobs

I have a Smart Folder set to select all items rated >0 and to reject all items coloured green (4) (ie. non-charity jobs)

I have another folder set to select all items rated >0 and to also all items coloured green (4) (charity jobs)

The first folder also rejects all unlabelled items.

This is a bit drastic for me, as it implies that I will have to label every item, everywhere.

I request that a rule which says 'is not 4' allows all other labels including unset ones

peter