Color light helps — Red and amber light help you sleep; blue light keeps you awake. Our team explains the science of bedroom lighting and what to actually use after sunset.
James on our team installed amber bulbs in every bedroom lamp three years ago and never went back. Here’s the why and the specific colours to look for.
The biology, briefly (Color light helps)
The retina has a special non-vision cell type — intrinsically photosensitive retinal ganglion cells (ipRGCs) — that responds most strongly to blue-wavelength light around 480 nm. When triggered, these cells signal the suprachiasmatic nucleus to suppress melatonin and wake you up. Red and amber light (above 580 nm) barely activates them, so melatonin keeps flowing.
By colour
| Light colour | Wavelength | Effect on sleep |
|---|---|---|
| Blue (daylight) | ~470 nm | Strong wake signal — keeps you alert |
| White / cool white | Mixed, blue-rich | Significantly suppresses melatonin |
| Warm white | ~3000 K | Mild melatonin suppression |
| Amber | ~590 nm | Almost no impact |
| Red | ~650 nm | No melatonin impact |
Practical setup
- Bedside lamp: amber or red bulb (Philips, IKEA and Mirabella all sell 2200K or below).
- Bathroom: dim warm white for the night-time bathroom run; avoid the bright LED that wakes you up.
- Smart bulbs: Philips Hue and IKEA Trådfri can be set to fade to amber after sunset.
- TV: any modern set has a “warm” or “movie” mode that reduces blue.
- Phone: enable Night Shift (iOS) or Bedtime Mode (Android) to scheduled hours.
What about pink and green?
Both have moderate effects on melatonin. Pink (~650 nm + some blue) is mild; green (~530 nm) is significantly disruptive — even worse than warm white in some studies.
The simpler version
If colour temperature feels confusing: anything labelled 2700K or below is reasonable for evening use. 3000K to 4000K is fine for kitchens and living rooms. 5000K or above belongs in offices, not bedrooms.
Daytime — flip the rules
The same biology means bright cool light in the morning is genuinely useful. 30 minutes of outdoor sunlight or a 10,000-lux SAD lamp anchors your circadian rhythm and improves sleep quality the following night. The blue/red rule isn’t “blue is bad” — it’s “blue at night is bad, blue in the morning is great.”
For independent guidance on sleep and wellbeing, the Sleep Health Foundation is a good starting point.
Colour light for sleep, room by room
The right colour light for sleep changes by room. In the bedroom, anything below 2700K is fine — warm-white bedside lamps and amber bulbs both work. In the bathroom, install a dim warm-white nightlight separately so the main bright LED doesn’t need to come on for a 3am visit. In the living room, switch to warmer evening lighting from sunset onwards via smart bulbs (Philips Hue, IKEA Trådfri) or a manual lamp swap.
Specific bulbs we use
- Philips Hue White Ambiance — adjustable 2200K to 6500K, programmable.
- IKEA Trådfri E27 — cheap option, 2700K warm white.
- Mirabella Smart Filament — amber filament look, 2200K, no app needed.
Test it cheaply
Before re-bulbing, swap one bedside lamp to amber and live with it for a week. Most people don’t notice the colour change after night two but report sleeping faster.
Children and screens
Younger eyes are more sensitive to short-wavelength light. For under-10s, no devices in the bedroom and warm-white reading lamps only. The same rule applies more loosely for teenagers — phone-free bedrooms remain the Sleep Health Foundation recommendation through to 18.
