The creators of The Red Balloon probably never had this in mind.
Aérophile, a French company that produces hot air balloons, has created a model that changes color to tell people how clean—or unclean—the Parisian air is that day. After gathering data from Airparif, an agency that monitors air quality in France, the balloon’s owners will adjust its color to correspond with the pollution level—green meaning excellent air quality, yellow signifying OK, and red meaning highly polluted.
Physorg reports that the balloon will be visible from 12 miles away, letting lots of Parisians find out about the air with a quick glance—presuming the sky is clear enough to see that far.
The balloon will be tethered in Parc Andre Citroën on Paris’s Left Bank, but it can do more than tell the French about their atmosphere: Thirty tourists at a time will be able to ride around the city in Aérophile’s air monitor.
However, if floating around Paris on your next European vacation sounds alluring, just make sure the balloon is green.