Overwriting global page rules

Hi all,
I am trying if it’s possible to effectively cancel out a global page rule with a “local” page rule but am struggling.

E.g. I have a global page rule that turns version BG colours red if a certain condition is met.
On one page I don’t want that to happen, so I set up the same rule as a local rule. This works if I want to assign a different BG colour, but if I leave the colour set to “no colour” the global rule takes effect again and things turn red when they should just not get a custom colour at all.

Am I missing something or is this a bug?

Cheers,
frank