Normally I would say: invert the colours and the problem is solved. But when you invert whitelisted, you get red, and when you invert blocked, you get green. So this is no solution. So other colours should be found for marked and blocked/whitelisted items.
In worst case, it could be let, like it is now, since it is only one click and the item is deselected; then you can see its status.
Is this image blocked or not?

Is this gif whitelisted or not?

Site with images for testing: http://filtersetx.fi.funpic.de/sandbox/
(should work with most filters, if not: add filter "*/RealMedia/ads/*" and "@@wikipedia.org" for example)