Adding colour label to non-empty folder

I've seen the earlier post from 2011, but I can't get the ideas presented there to work.

Eventually, I would like a rule that adds a red label to a folder when it contains files and remove that label (ie no label) when the folder is empty.

I've tried the suggested:

if all of the following conditions are met

Kind is Folder
Size is greater than 0kb

Set color label "red" (red is ticked)

I haven't got as far as trying to reverse this action for an empty folder because I can't get this first bit to work.

I've also tried putting the files in a subfolder, in case this rule was looking for a sub-folder inside the folder the rule was being applied to. The files are currently in the same folder as the rule is being applied to.

I have also tried a few other combinations,but I'm not able to get a red label applied to the folder.

I then tried the subfolder rule option:

with If any of the following conditions are met,
with a subfolder rule
If any of the following conditions are met for "any file or folder in the same folder" (but cycled through all the options
Size is greater than 0kb

set color label to red

I can't get this to work either. I assume I am missing the obvious?

I can't check right now, but there is a possibility I had actions paused, which is why nothing is happening when a save a rule.

I need to check when I get back to the computer.

It seems I am adding the label to the files inside the folder and not to the folder itself. Is there a way to add the label to the folder?

The simple

Kind is folder

Number of of items is not 0

Set color label "red"

is working, except for the labelling files rather than the folder.

I hadn't picked up on being for labelling files.

Rules operated on the contents of the folder being monitored. You can't have rules apply themselves to the monitored folder itself. For that, you will need to monitor one folder up.