As a child growing up in El Paso I remember the El Paso Natural Gas Company’s blue flame which was visible from a distance, sitting high atop the gas company’s downtown building. Even though most of us called it the blue flame, its color could change each night, letting us know what to expect of the weather the next day. There was even this mnemonic for the meaning of the different colors,
When the flame is blue, no change is due.
When the flame is red, warmer weather’s ahead.
When the flame is gold, cooler weather foretold.
A flickering flame means wind, rain or snow.