"I think people here in Brazil have a greater perception of colour than most of you westerners" a Brazilian friend of ours tells us. "We can tell the difference between the traffic lights that you might not even be able to see". I nod, slightly bemused.
"You see this light here?" he says, coming to a stop, "this light is red and so we stop as you would in your country. This light however," as we approach the next junction, him briefly glancing around, "this is not so red" and we sail through, closely followed by a bus that, it would appear can also tell the difference.