BulbMatch: Light Bulb Color

One bulb goes. The other two still work. Which box do you buy?

BulbMatch reads the light from a bulb that still works and names the bulb that matches it — 2700K warm white, 3000K soft white, 4000K cool white or 5000K daylight — in the words printed on the box. All on your iPhone: no account, no upload, no photo saved.

▸ A SHOPPING ANSWER, NOT A PHYSICS ANSWER
Every other tool that reads light hands you a raw Kelvin figure and leaves the shopping to you.

• "2700K — Warm White", and every phrase that bulb is sold under
• Brands print "soft white" on bulbs of different temperatures — BulbMatch says so plainly and gives you the number to match instead
• Confidence in plain English: steady and well clear of the next type, or a close call worth a second reading
• When two types are genuinely in play it names both, instead of picking one to sound certain

▸ IT WILL NOT HAND YOU A NUMBER THAT IS STILL MOVING
The button stays off until the reading holds still.

• The live reading is greyed out until it settles — a jittering number is not an answer
• "Frame too bright — the centre is clipping." "Frame too dark — nothing to read." It tells you what is wrong, not just that it failed
• White-paper mode — light plain paper with that bulb alone and read the paper; it reads far tighter than pointing straight at a bulb
• Four bulb types, never four digits — the camera's estimate does not support false precision, so the app does not print any

▸ SAVE THE HOUSE, NOT JUST THE ONE LAMP
Measure a fixture once and the next bulb is a two-second lookup.

• Rooms and fixtures — kitchen ceiling, 3 bulbs, E26, with a colour chip you can read at a glance
• Copy a shopping list into Notes or Messages before you leave: Kitchen ceiling — 3 × 2700K (sold as "Soft White" or "Warm White"), E26
• Every reading kept per fixture, so you can see whether it was a close call
• A reading taken on another iPhone is flagged — camera sensors disagree, and the app will not pretend otherwise

▸ ON YOUR IPHONE, FULL STOP
There is no server to send anything to.

• Works in airplane mode
• No account, no sign-in, nothing to create
• No photo is ever saved — frames are read and discarded
• Privacy label: Data Not Collected

▸ FREE
• Three measurements, with the full result and the confidence line
• One saved fixture
• White-paper m