That orange glow that now falls from the island's streetlights isn't your imagination, since for years the same light poles cast a blue-green hue.
Keys Energy Services says it is finishing up a complete change-out of the bulbs in thousands of streetlights across the Lower Keys.
The switch from mercury vapor bulbs to high pressure sodium versions is the result of the Energy Policy Act of 2005, which banned the manufacturing of new mercury vapor bulbs for new streetlights as of 2008 and the sale of them for existing fixtures by 2016.
Signed by President George W. Bush, the act says phasing out mercury vapor lights will "protect the environment" and promote energy efficiency in lighting.
The high pressure sodium bulbs reportedly are twice as efficient as the old bulbs, yet still contain some mercury, which is classified as a hazardous material by the government.
Keys Energy manages the 5,000 streetlights in the city of Key West and in the Lower Keys for Monroe County.
Key West's streetlights went completely high pressure sodium last year. The rest of the Lower Keys aer due to comply by year's end, said Keys Energy spokesman Julio Barroso in a statement.
"The change-out has been seamless to Keys customers," Barroso said. "The (new) streetlights have the same rated lifespan as the (old bulbs) and they give increased light and efficiency at lower wattages."
The only difference, Barroso said, is the new orange color of the lights. In the past, the lights cast a blue-green haze.