Tier two is high alert, and we’re told this via bus hoardings in London at present. On the design front, the colour scheme for this seems to be Lucozade orange, and presumably they go for bright MAJOR ALERT red for Tier three. However, the fact that tiers run up… rather than down (like the pop charts where the single figure 1 is the best) means that there is, theoretically, a Tier 4… and 5. What’s Tier 4? Yellow? Or would that be 1? BLACK maybe for Tier 5, to remind us of the Black Death, which wasn’t particularly kind.