Certain types of light can affect your mood and quality of sleep. Red light may help, while blue light from phones or screens could interfere with falling asleep or the quality of your rest.

You may have heard that you should avoid bright lights before bed. While this is good advice, it turns out that some colors of light may disrupt your sleep more than others.

Melatonin is a hormone that largely controls your body’s natural sleep-wake cycles. Specialized photoreceptors in your eyes send information back to your brain and influence your production of melatonin.

This research review has found that these receptors are most sensitive to light with wavelengths around 450 to 480 nanometers (nm). To most people, this light appears blue.

There’s still a limited amount of research looking at the effects of other light colors on our sleep cycles. However, there’s some evidence that warm colors may help lull you to sleep more quickly than cool colors.

Let’s look at which colors have the potential to lull you to sleep the quickest and which might have you tossing and turning all night.

Until now, most studies examining the best types of light to stimulate sleep have involved rodents. However, because rodents are nocturnal and colorblind, it’s hard to draw conclusions from these studies.

Limited research on humans suggests there is some evidence that red light may help stimulate sleep. There’s also some evidence that individual preference may also play a role.

Since pink light consists of a combination of red and purple light waves, it could also be beneficial — in theory. However, there’s no research backing the claim at this time.

Red light

Some early, nonhuman research shows that red light may allow for better sleep.

This 2023 research notes that red light does affect sleep quality and alertness as a person is preparing for and trying to fall asleep. That research specifically involved people who experience insomnia.

While more comprehensive research in humans would be needed, this rodent study notes that red light may help you fall sleep quicker and improve the quality of your sleep.

This 2017 study also on mice found that red light at an intensity of 10 lux or higher had the potential to induce sleep. The researchers noted that light under 10 lux had no effect.

Individual differences

In this 2017 study, researchers found evidence that individual taste may also play a role in determining which color light is best for inducing sleep. In the study, researchers ran two different experiments.

In the first experiment, they exposed participants to white light, a random color, or their self-selected preferred color. The researchers observed that participants exposed to their preferred light color fell asleep significantly quicker.

ColorTime to fall asleep
white18.8 minutes
random nonpreferred color18.1 minutes
preferred color11.8 minutes

In the second experiment, the researchers also included a group that was only exposed to darkness.

Once again, the researchers found that the group exposed to their preferred color fell asleep significantly quicker than participants in the other groups.

ColorTime to fall asleep
white21.2 minutes
darkness21.1 minutes
random nonpreferred color16.8 minutes
preferred color12.3 minutes

Babies and children seem to also be negatively affected before bed by blue and white lights. That’s why experts often recommend warmer colors for night lights.

A 2018 study examined the impact of two colors of light — whitish-blue and yellow — on the sleepiness levels of children and adults.

The researchers found that children had greater melatonin suppression than adults in both cases, but their melatonin was even more suppressed when exposed to yellow light.

Some people worry that exposing infants to bright lights at night while nursing could negatively affect their health.

These colors may not be ideal for helping you sleep.

Blue: This 2018 study notes that exposure to blue light can negatively impact your sleep quality. Electronic screens, LED lights, and fluorescent lights can all contain blue light.

Violet: Research from 2024 also found that violet light may have a similar effect as blue light.

Green: Older research over the past few decades also notes that green light can negatively affect melatonin levels for your sleep.

Many factors can affect the quality of your sleep. Here are some tips to help you sleep better.

Habits to avoid before bed

  • exposure to electronic screens, such as phones or television, before bed
  • ingesting caffeine late in the day
  • drinking too much water before bed
  • consuming alcohol
  • going to bed and waking at irregular times
  • long naps during the day

Habits that may improve sleep

  • exposing yourself to bright light during the day
  • exercising regularly
  • sleeping on a comfortable mattress and pillow
  • having a quiet sleeping area
  • doing something relaxing before bed
  • keeping your room at a comfortable temperature

There’s some evidence that red light may induce sleepiness. However, more human research is needed to back this theory.

Blue light can have a negative effect on your melatonin levels. But exposure to green and purple light could also potentially hinder your ability to fall asleep. More research is needed to fully understand their effects.