A few years ago, most of Chicago’s streets, alleys, and parks took on a hazy orange glow. But for the past two years, the city has slowly replaced the warm-colored, high-pressure sodium bulbs with more modern LED lights.

In the 1970s, when the city first began installing the high-pressure sodium bulbs people were not enthusiastic. Skeptics likened the streets to a yellowy washed-out, nightmare. But now, the orange light is part of the city’s character—and its particularly beautiful if you’ve ever gotten an aerial view of the street grid while flying overhead to O’Hare. So, it’s understandable that some Chicagoans might feel bit of reluctance to the whiter, brighter lights.

Is the change a good thing though?

Well, that’s tricky to answer. On one hand, the city’s Smart Lighting Program is saving money. So far 156,000 of the 270,000 high-pressure sodium light bulbs have been converted. That translates into savings of 70 million kilowatts hours of energy which is equivalent to $3.4 million. Ultimately, the city hopes it’ll save about $100 million since LEDs operate with just a fraction of the electricity that the older streetlights use. The lights will also need less replacing and an automated system will tell city workers when a replacement is required.

On the other hand, some researchers believe the brightness of Chicago’s new lights can adversely affect residents’ health, local wildlife, and even crime rates. WBEZ investigated the issue for an episode of Curious City, and found that some of the concerns about the level of blue spectrum light were warranted.

While the new lights do use more blue light (which is more akin to daylight), the city sought the guidance of experts from the U.S. Department of Energy, the American Medical Association, and the Illuminating Engineering Society to determine a safe color temperature. Plus, the new fixtures focus light doward toward streets and sidewalks reducing light pollution in people’s homes and the night sky.

The lighting program doesn’t replace every single fixture in Chicago—so some of the orange light will remain. The city is replacing all the “cobra head” style lamps, which do make up the bulk of the city’s system.

Eventually, about 85 percent of the city’s public streetlights will be replaced with LEDs. So, before the last golden glow dies out, let’s admire the city under its older streetlights.