Kind of confused...

I'm a bit confused on how to use "Run rules on folder contents".
What i was trying to achieve is:
Can you help, please?
thx,
g
What i was trying to achieve is:
- check the MASTER folder
check its subfolders
if they contain images, check if they're RGB
if they are, label RED the container folder
Can you help, please?
thx,
g