Twelve canaries with different colors representing each of the months. Remove the canaries where the color corresponds with the month. Make absolutely no claims beforehand as to what the colored canaries represent - people should be able to figure it out (3 green, 3 red, 3 brown, 3 blue: take a guess?)

You are saying nothing at all. Just adding/removing images on a page called /canary/

IANAL, but I'd be interested how the above would be illegal.

They would contend that this is just a wink-and-a-nod way of providing the information you aren't allowed to provide. It doesn't matter if you disclose the information in English, French, or binary, it's still illegal. If you have it in a page called /canary/ and it obviously corresponds with NSLs you'd be in some hot water.

People tend to assume the court system is like a machine when it's very human at its core. A judge isn't going to say "well you technically didn't reveal any info so you're kosher," a judge is going to be pissed that you decided to low-key defy his/her order.

AFAIK, even a binary "canary" has been untested in court and might not even stand on its own (yet many companies have one).

There are countless loopholes in various legal systems across the world that "get a pass". It's often a matter of finding the right loopholes.

One example is gambling in Japan. Illegal. But if you play at a pachinko slot for a chance to win some tokens you can go next door and there is a business that will buy the tokens from you! It really is convenient someone is willing to buy these otherwise useless tokens. :)

I'm sure if I put some thought into it I could find a few more loopholes that are a "wink and a nod" away of being illegal. Of course, my suggestion might be too blatant and the company would be dragged to the courts. But even a single canary could still warrant being dragged to court over.

This is true, but there's a core fundamental issue. There has never been any legal support for the idea that the government can compel speech (such as forcing the continued false inclusion of a "binary" canary). There is a clear basis of support for the idea that the government can regulate speech, whether it's English or cryptic colored circles. So trying to speak (publish canary info) in any sort of cryptic way will still always be more risky than choosing not to speak (omit your canary). The government could always drag you to court over anything, but you still want to keep them at the downhill end of the battle.