What color light helps you sleep? In the evening, dim and warm is best. Red and amber light disturb your body clock less than blue or bright white light, but brightness matters just as much: even ordinary room light can delay melatonin. Switch to low, warm lamps after dark and keep the bedroom dark overnight.
Melatonin is a hormone that rises in the evening and helps time your sleep. Harvard Health explains that exposure to light suppresses melatonin, which influences your circadian rhythm, the roughly 24-hour clock that tells your body when to feel sleepy.
A well-known NIH-funded study by Gooley and colleagues looked at 116 healthy volunteers aged 18 to 30 living in a sleep lab. Researchers compared ordinary room light (under 200 lux) with dim light (under 3 lux) in the 8 hours before bedtime. Room light:
delayed the start of melatonin in 99% of people tested (103 of 104)
shortened the body's melatonin "night" by about an hour and a half
cut melatonin before bedtime by about 71% in people whose melatonin had already started rising
This was a lab study of young adults with long, controlled light exposures, so it does not tell us exactly what happens in your living room. It does show that you do not need a bright screen to affect your body clock. Normal indoor lighting can do it.
Color does make a difference. Harvard Health says that while light of any kind can suppress melatonin, blue light at night does so more powerfully. In one Harvard experiment, blue light suppressed melatonin for about twice as long as green light. Red light, Harvard notes, is less likely to shift your circadian rhythm and suppress melatonin.
Most sleep-friendly: dim red, amber or orange light. Sleep tips published with a Northwestern Medicine study say amber or red/orange light is less stimulating for the brain.
Fine in the evening: warm white light kept low. The Sleep Foundation says low brightness and a warm color temperature may help you relax and get ready for sleep.
Least helpful at night: bright white or blue-toned light. The same tips say not to use white or blue light, and to keep any light far from the sleeping person.
It is tempting to buy a red bulb and stop there, but brightness counts too. Harvard Health reports that a mere 8 lux, a level most table lamps exceed, can affect your circadian rhythm, and that even dim light can interfere with melatonin. The Gooley study above used ordinary room light, not colored light, and still saw clear effects.
So aim for both at once: warm and dim. A low amber lamp is better than a bright overhead light of any color. The Sleep Foundation's simple rule is to keep your lights dim when preparing for bed.
Swap overheads for lamps after dinner. The Sleep Foundation suggests a small, low-power lamp to help you move toward bedtime.
Choose warm bulbs. Look for "warm white" or amber on the box for the lamps you use at night.
Fit dimmers where you can. A dimmer on the living room or bedroom light lets you lower brightness step by step through the evening.
Use amber or red night lights. For hallways and bathrooms, pick dim amber or red night lights placed low, near the floor, as Northwestern suggests.
Schedule smart bulbs. If you have smart bulbs, set a routine that shifts them warm and dim a couple of hours before bed and turns them off at bedtime.
Get bright light by day. Harvard Health recommends lots of bright light during the day, which can boost your ability to sleep at night.
Screens are their own topic. For phone, tablet and TV settings, see blue light and sleep.
This is an example only, for a 10:30 p.m. bedtime.
7:30 p.m.: Overhead lights off in the rooms you use. Warm lamps on.
8:30 p.m.: Dim the lamps or switch to one low lamp. Smart bulbs drop to a warm, low setting.
10:00 p.m.: Only a small bedside lamp. Hallway night light on.
10:30 p.m.: Lights out. Blinds closed.
Once you are asleep, darker is better. In an NIH-supported Northwestern study, sleeping a single night in moderate light (100 lux) instead of dim light (3 lux) raised heart rate during sleep and led to insulin resistance the next morning. The article suggests blackout shades or eye masks if you cannot control outdoor light, and moving your bed so outdoor light does not shine on your face. For more ideas, read how to make your bedroom darker.
If you need a light for safety, especially for night-time bathroom trips, Northwestern advises a dim light close to the floor. The Sleep Foundation suggests a warm night light placed away from your bed.
Lighting changes are easy to try, but they will not fix every sleep problem. The NHS suggests seeing a GP if changing your sleep habits has not helped, if you have had trouble sleeping for months, or if poor sleep is making it hard to cope with daily life.
This is general information, not medical advice. Talk to your doctor or pharmacist about your own situation.
Red light is less likely to shift your body clock or suppress melatonin than blue light, according to Harvard Health. Keep it dim, because brightness still matters.
Yes, if it is low. The Sleep Foundation says low brightness and a warm color temperature may help you relax before sleep.
A dim amber, red or orange night light placed low and away from the bed. Northwestern's sleep tips advise against white or blue light.
The Sleep Foundation says sleeping with the lights on is generally not ideal. If darkness feels hard, use a dim, warm night light away from the bed, or one on a timer.
Sleepward: Bedtime Routine has a gradually darkening wind-down screen and an editable routine for the end of your evening, plus a Minimal Mode with one action, one timer and one Finish button. It is still a screen, so pair it with the warm, dim lamps above. It is free with optional Pro purchases and has no accounts or ads.
Get Sleepward free on the App Store
Light and Sleep: Effects on Sleep Quality (Sleep Foundation)
Close the blinds during sleep to protect your health (Northwestern Now)