Philips Hue White Ambiance A19 (1100 lm, 2-pack)

The current Hue White Ambiance A19 is the best fit for “circadian lighting” in the literal sense: one bulb that is bright and cool in the morning and warm and dim at night, on a schedule. Philips now rates it from 1000K to 20,000K, and it dims down to 0.2% of full output. Those two numbers matter most for evenings, because the expert target is under 10 lux melanopic EDI in the 3 hours before bed. Very warm and very dim gets you there; warm alone may not.

The automation comes from the Natural light scene. It moves through a default schedule of warm-to-cool white that you can edit block by block, with each block at least 30 minutes, according to Hueblog’s write-up of the feature. It needs a Hue Bridge and at least one White Ambiance or White and Color Ambiance bulb in the room. Without a bridge, the bulbs still work over Bluetooth for manual control from the app.

What it does badly: it is white only. At 1000K it is a deep orange, but Philips does not publish a spectrum, so you cannot check how much short-wavelength light remains at the warm end. If you want a saturated red for the bedroom, the White and Color Ambiance version of the same bulb adds colour for $59.99 each. The bridge also adds real cost to a small setup.

How it compares: LIFX SuperColor needs no hub and includes colour for less money, but its warm end stops at 1500K and its dimming stops at 1%. A dedicated amber bulb such as the BlockBlueLight Sweet Dreams costs less and needs no app, but it is amber all day.

The 2-pack listed here is the 1,100 lm (75 W-equivalent) version.