Most questions are answered below in under a minute. If yours isn't, email us — a human reads every message, usually within 48 hours.
Hold the phone steady, fill the reticle with the surface, avoid glare and shadows. Use the freeze button to lock a reading before saving it.
Tap the seal icon on the Capture screen, frame an 18% neutral gray card under your working light, and tap Calibrate. Create one profile per lighting condition.
History and calibration profiles sync automatically through your private iCloud. Just be signed into the same Apple Account with iCloud Drive enabled.
Because the light changed, even if your eyes didn't notice. Auto-exposure and white balance shift continuously in Quick mode. For stable, repeatable numbers, calibrate and use Accurate mode: it locks the camera and corrects readings toward a standard illuminant (D65 or D50).
Any 18% neutral gray reference card works — they cost a few euros in photo shops. A neutral gray card stock or the back of a photographic gray card is fine too. The key is that it's truly neutral (no color cast).
Honestly: readings are indicative. A phone's RGB sensor is not a spectrophotometer. With calibration under stable light you get remarkably close, repeatable values — great for matching paint, fabric and design work. Metallic, pearlescent and iridescent finishes change with viewing angle and are out of reach for any camera-based tool.
Quick mode reads whatever the camera sees, with continuous auto-adjustment — instant and great for browsing colors. Accurate mode locks exposure, white balance and focus, then applies your calibration profile via a Bradford chromatic adaptation, so Lab values are meaningful and comparable.
Yes. On the Capture tab, tap the photo button, pick an image from your library and tap any point. The sampling patch size (Settings → Colors) also applies here — increase it for noisy or textured surfaces.
Colors: long-press a swatch in History and choose Delete, or open it and use the ··· menu. Profiles: in Settings, swipe left on a profile to delete it (swipe right to rename).
Completely. Capture, calibration and history all work without a connection. iCloud sync simply resumes whenever you're back online.
Check that both devices are signed into the same Apple Account, that iCloud Drive is enabled, and that Colorimeter is allowed under Settings → [your name] → iCloud. Sync is handled by Apple and can take a few minutes the first time.