Why are there blue turtles and red on the health code?

Health code blue represents people with normal body temperature, and red represents key people with fever.

Health code green and blue are a grade, both indicating safety. Some places are blue and some places are green. Green code: pass code. Yellow code: quarantine will be carried out within 7 days, and the health punch for 7 consecutive days (no more than 7 days) will turn to green code normally. Red team: quarantine 14 days, health clock-in 14 days normally turns to green code.