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Bathroom | The mirror light should change with the hour

Cool white to wake you, warm amber at 3am so it does not chase your sleep away. Six periods, one fixture.
November 20, 2025 by
Bathroom | The mirror light should change with the hour
渥屋科技股份有限公司, 系統管理者
Bathroom

SMART HOME BUTLER · BATHROOM

The mirror light should change with the hour

Cool white in the morning so you wake up and can see properly; warm amber at 3am so it does not sting and does not chase your sleep away. One fixture, six different versions of itself.

6
periods, each with its own settings
2200K
the night-time warmth that lets you sleep
5000K
daytime white, so you can see

Most bathrooms have exactly one kind of light

Brushing your teeth, putting on make-up or shaving in the morning, you need to see clearly, and cool white keeps skin tones honest. Get up at three in the morning and that same light hits your face like a bucket of cold water — twenty or thirty minutes gone before you get back to sleep.

Those two needs are opposites, but most homes only have one switch and have to pick one. Usually it gets specified for the morning, and then wakes you up properly every single night.

There is no need to choose. If the light knows what time it is, it can decide for itself what to look like.

Why the colour matters at night

Your body reads light to decide whether it is day or night. High colour temperatures and blue light suppress melatonin, the hormone that makes you sleepy. A cool white mirror light at 3am is effectively telling your body that morning has arrived.

Warm amber interferes far less. Set that night period to around 2200K, dim enough to see where you are walking, and most people get back to sleep without much trouble.

2200K 4000K 5000K 4000K 3000K 2200K 100% 50% 0% brightness 00 05 08 17 20 22 24 The background is the actual colour of the light. Warmest at both ends, coolest through the middle of the day The line is brightness. Only 15% overnight — just enough to see your feet
A full day of mirror light. You never switch anything; it already knows which version it should be.

One day at the mirror, in six moments

The chart above is the whole day seen from above. In practice what you meet is the six moments below, and the clock times are defaults rather than rules.

  1. 00:00 – 05:00

    The 3am trip you barely wake up for

    You push the door open with your eyes half shut, and you neither squint nor reach for a dimmer. At 2200K and 15% the light picks out the basin and little else, and your face in the mirror stays vague — which at that hour is not something you needed anyway.

  2. 05:00 – 08:00

    The light brightens while you brush

    It starts at 4000K and 60%, still faintly amber. By the time you look up from brushing, the same fixture has walked itself to 5000K and 100%. You touched nothing; the period ramps on its own and your eyes come round with it.

  3. 08:00 – 17:00

    Home in the day, washing your hands

    Flat 5000K at full output, no movement at all. Touch up lipstick at lunch, glance in the mirror after washing your hands, and the colours match what the street will show you ten minutes later.

  4. 17:00 – 20:00

    Through the door, straight to the basin

    Down to 4000K and 80%. The step is small enough that you rarely register it, yet your eyes have started coming down from a full day at full intensity. It is the one setting here you are meant not to notice.

  5. 20:00 – 22:00

    The shower and cleanser hour

    3000K at 60%, and the warmth is now obvious. Once steam fills the room that warmth reads as comfortable rather than dim, and there is still enough light to take make-up off without leaving patches.

  6. 22:00 – 00:00

    Last visit before bed

    The final switch-on of the day returns to 2200K, this time at 25% — a little above the small hours, because you still have a face to wash. The reflection stays soft on purpose: what you need now is not detail, it is not being woken up by your own bathroom.

Why each period is set that way

The same day laid out from another angle: where each of those numbers comes from.

PeriodColourBrightnessWhy
00:00–05:00 night2200K15%Enough to see your feet. No glare, no lost sleep, back to bed without trouble
05:00–08:00 morning4000K → 5000K60% → 100%Warm to cool, helping you wake. Ramping is gentler than jumping straight to full
08:00–17:00 day5000K100%Brightest and whitest, for accurate skin tones when shaving or applying make-up
17:00–20:00 evening4000K80%Starting to cool down — the transition from activity to rest
20:00–22:00 night3000K60%Clearly warm. Plenty for showering or removing make-up without waking you up
22:00–00:00 pre-sleep2200K25%The last stretch. After brushing your teeth you are heading to bed, so the light should stop interfering
The boundaries are not sacred. These six are a starting point — shift them to fit your own routine. Night owls should push the pre-sleep block later; early risers should pull the morning block earlier.

Four things it takes care of

Sleep

A 3am trip no longer wakes you properly. On its own this is usually worth more than the other three put together.

Seeing accurately

Make-up, shaving and checking how you look all need enough light at the right colour. Warm amber will lead you astray.

No glare

Walking from a dark room into a bathroom at full brightness hurts. With periods, the light matches the state your eyes are already in.

Nothing to manage

No extra switch to learn, no scene to pick. You press the same switch you always did — it simply comes on right every time.

Different people, different settings

Your situationWhat to adjustHow
You wear make-upThe daytime blockFull brightness, colour up to 5400K — close to daylight, so foundation shades match
Shift workAll six periodsShift them to your actual routine, not the clock. Your day may be somebody else's night
Older adults at homeThe night blockRaise 15% to 25%. Safety outranks sleep quality — seeing the floor prevents falls
Light sleeperThe night blockDrop to 2000K and 10% to keep the disruption as small as possible
Bathroom has a windowThe daytime block70% is plenty — daylight is already doing half the work

What you need to have

What it doesCategory in the systemEssential?
Colour-adjustable mirror lightlightYes
Detect someone enteringbinary_sensorNice to have
Manual overrideswitch on the wallNice to have
The light has to support colour temperature for this to mean much. A brightness-only fixture still works, but you lose half the benefit. If yours is on/off only, replacing it with a tuneable one is the single most worthwhile piece of hardware here.
Awkwardly controlled light? Some fixtures expose brightness and colour as two separate entities, which is unpleasant to work with. The template_light_composer component merges them into one normal-looking light, after which every automation can treat it like any other. It ships with the hub.

How the whole thing works

Time of day which period applies Someone enters sensor or switch adalight blueprint looks up that period Set brightness, 15% to 100% Set colour, 2200K to 5000K
Two inputs, two outputs. Inside the blueprint it is a six-row table, and all it does is set the light from it.

Use the ready-made blueprint

The hub ships with 22 tested automation blueprints — think of one as a fill-in-the-blanks form. This uses adalight, which exists precisely for "six periods a day, each with different light". All you supply is the six sets of numbers.

FieldWhat it meansSuggested
Which lightThe mirror light—
Period boundariesYour routine, not the clockSee the table above
Brightness per periodSix percentages15 / 60-100 / 100 / 80 / 60 / 25
Colour per periodSix Kelvin values2200 / 4000-5000 / 5000 / 4000 / 3000 / 2200
When it appliesWhenever the light is switched onOn switch-on
Manual adjustments are not overridden. Turn the light up by hand and adalight leaves it alone. It reapplies the period's settings the next time the light is switched on, not while you are standing there.

One optional addition

If you wantBlueprintWhat it does
Lights off when you leavebinary_sensor_trigger_lightTurns the light on when someone is detected and off a few minutes after they leave. The two pair up: this one handles on and off, adalight decides what "on" looks like

You do not have to set it up — just say the word

Those six sets of numbers are not something you have to type in by hand. The WOOWTECH hub ships with HA-MCP, so an AI assistant can reach into your system directly, do the work, and then check for itself that the light really comes on the way that period says it should.

YouMake the bathroom mirror light follow the time of day. Very dim and warm overnight, brightest and coolest during the day, warming up gradually through the evening.
pi agentFound the mirror light — it supports 2200K to 6500K, so this works. I have set six periods: 2200K at 15% overnight, up to 5000K at full through the day, cooling off from the evening, back to 2200K at 25% before bed. I simulated the night period, switched the light on, and it did come up dim and warm.
YouMy mother lives with us — is 15% too dark to be safe?
pi agentThen raise the night block from 15% to 25% and keep the colour at 2200K. That gives clear sight of the floor without being stimulating. Done, and re-tested.

Prompts you can copy straight across

Every block below can be copied whole, and the button on the right does it for you. Pick the one closest to what you want; you do not need all five.

The simplest versionuse this if you just want it running
Make the bathroom mirror light follow the time of day,
in brightness and in colour.
Very dim and warm overnight, brightest and coolest during the day,
warming down gradually through the evening.
If the light cannot change colour temperature, just do the brightness
half of it and tell me that is what happened.
The full versionsix periods, trigger timing and extras included
Set the bathroom mirror light to six periods across the day. Use the ready-made blueprint, do not write a pile of custom rules.
First check whether the light supports colour temperature and what its Kelvin range is; if it does not, tell me before you build anything.
The six periods: 00:00 to 05:00 at 2200K and 15%; 05:00 to 08:00 rising from 4000K at 60% to 5000K at 100%;
08:00 to 17:00 held at 5000K and 100%; 17:00 to 20:00 down to 4000K at 80%;
20:00 to 22:00 at 3000K and 60%; 22:00 to 24:00 back to 2200K at 25%.
If it cannot reach 2200K, use its lowest supported value and tell me what that is.
Apply the settings at the moment the light is switched on, never halfway through a shower.
If there is an occupancy sensor in the bathroom, add lights-off a few minutes after I leave.

Once it is built, test it yourself, confirm it really works, and then tell me which devices you used.
Adjusted for your homeuse this one if you work night shifts
I work nights: I sleep in the day and I am up all night,
so do not set the periods by the clock.
Put the brightest, coolest block in the three hours after I get up,
and the dimmest, warmest block in the daytime hours before I sleep.
I wake around 3pm and go to bed around 7am, so shift all six to match.
List the actual start and end times of each period when you are done.
Changing it laterone sentence adjusts a setting
The overnight block at 15% is too dark, raise it to 25%
and leave the colour at 2200K.
Start the pre-sleep block at 23:00 instead of 22:00, I am going to bed later.
The daytime block can drop to 80%, the bathroom has a window and it is too bright.
Leave everything else alone.
When something goes wronglay the settings out first
The mirror light does not look like what I asked for, but I cannot say what is off.
Do not change anything yet. Lay the six periods out in a table for me:
the brightness and colour temperature each one is really using now,
next to the numbers I originally gave you, and mark every cell that differs.
I will read it and then decide.
One caution: the HA-MCP connection URL is the key to your home. Do not post it publicly, and do not give it to services you do not trust.

Common questions

My light only dims, it cannot change colour
Then do the brightness half only — it still helps. The difference between 15% overnight and 100% during the day is already obvious. Add colour later when you replace the fixture; the rule does not need rebuilding, you just fill in the extra fields.
Does it flash bright before dimming?
A good fixture will not — it comes on directly at the specified brightness and colour. If yours briefly goes to full first, that is the light remembering its last state, and it can usually be changed in the light's own settings to "restore previous command".
Does it change colour mid-shower at a boundary?
No. adalight decides which settings to use at the moment the light is switched on; it will not shift while you are standing under the shower. If you cross a boundary and want the new setting, switch it off and on again.
Will my manual adjustment get reverted?
Not during that session. Turn it up and it stays up until you switch the light off. The next switch-on reapplies the period default. That is deliberate: an immediate need outranks the automation.
My routine is irregular — how do I set the periods?
Base them on your most common pattern; being occasionally off does no harm. If the variance is large, ask the assistant to key the periods to sunrise and sunset rather than clock times, or add a manual mode switch.
Do I have to rebuild it to change the numbers?
No. Just say "the night setting is too dark, make it 25%" and the assistant will find that rule and edit it.
good nights

A month from now

You get up in the night and fall back asleep quickly. Those "well, I am awake now" nights have become much rarer.

And in the morning you look more like yourself in the mirror, because the light is finally the right colour.

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