[fapjacks]

That's sort of what they're doing. It's just a two-bit QR code: Red, and Not Red.

[gumoro]

So, one bit ;)

[fapjacks]

Hah! Yes, totally. Haha I wonder why I said that?

[BraveNewCurency]

There is also a "not decided yet" state. Hence, you were right, it needs two bits. :)