I noticed today that almost all taps, including those in public places, distinguish their hot or coldness through entirely two dimensional methods... either through H and C decals or by being blue or red in places. Very rarely is the hot top very differently shaped from the cold tap. I'd hate to be partially sighted and needing some hot water (or wanting to not be scolded by the taps that seem to link directly to the magma chambers brewing evil in the deepest bowels of the earth).
I also wonder at the proportion of left or right handed sinks... I've never noticed any rhyme or reason affecting the placement of taps. Do budding water systems engineers have a morning of their training courses set aside to learn that hot should be on the left, is there a big book somewhere? Perhaps the modern plumber is mildly discordian and injects that little bit of chaos into everyone's lives by flipping a coin to decide which side is hot. I think we should be told.