In Greenland they had a system to encode what purpose a building had. For example, if you were in a medical emergency, you would look for a yellow building.

> Red buildings signified churches, schools, teachers’ or ministers’ houses. Yellow colours were assigned to hospitals, doctors, and health care personnel. Green was at first the symbol for radio communication and later became the colour of telecommunications. The colour blue was often reserved for fish factories. Police stations were black.

https://www.polar-quest.com/blog/greenland/the-backstory-of-...