While LED lightbulbs are more energy-efficient and can last dozens of times longer than their older incandescent cousins, the bluish light they produce feels much more sterile and is believed to hurt sleep by suppressing melatonin and disrupting the circadian rhythms, writes Rahul Rao for Popular Science.

While scientists are already working on creating friendlier LED bulbs that would alleviate the blue light issue, Brandon Mitchell, a physicist at West Chester University, believes this is not enough.

Mitchell thinks that while blue-hued white bulbs are a problem during the evening and night, they work well in the morning and afternoon due to sunlight changes throughout the day. He believes LED bulbs should reflect that.

“If it’s still a bright day outside, if it’s 2 PM, you don’t want a yellow bulb, you want a white bulb,” he said. “Then if it’s 7 PM, you don’t want a white bulb, you want a yellow bulb.”

And while color-changing LED lightbulbs already exist, they are expensive and there is still a ways to go before they become commonplace.

Read more about LED lightbulbs in Popular Science.