Is there a reason why they used those specific colors? I don't understand why a hospital would be yellow or a police station would be black by default. My guess would be white and blue, respectively.
Snow in the air is probably a bigger problem than snow on the ground, blizzards with 20m or less visibility aren't that uncommon far north, really easy to get lost and die during those since the snow also blots out the terrain unlike fog.
Imagine trying to find a hospital under these conditions, vibrant color coding helps save lives then: