Shades are chosen under daylight beside a window, never under the operating lamp — the same ceramic can look correct in the chair and artificial on the street.
Two surfaces can match under one light source and differ under another, because they reflect different parts of the spectrum. Dental operating lamps and most clinic ceilings are cool and intense, which suppresses the yellow-red end and makes very bright shades look reasonable. Midday daylight is broader and more neutral, and it exposes the same shade as flat. We therefore take and confirm every shade beside a window, with the operating light switched off and strongly coloured clothing covered.
Enamel brighter than the whites of your eyes is the point at which observers start describing a smile as artificial, and that is a check you can make yourself in a mirror. Skin tone matters less than people expect; age matters more, because enamel darkens gradually and a shade that suits twenty-five reads as a set of veneers at sixty. We hold the shade tab beside the eye and beside the lower lip, and photograph both, so the choice is documented rather than remembered.
BL1 to BL4 sit above the natural range of human enamel. They photograph well under stage and flash lighting, which is why they dominate social media, and they are a legitimate choice as long as you know what you are choosing. Most of our patients settle between A1 and BL3 once they have seen both in daylight. What we insist on is that the decision is made from a mock-up in your own mouth, not from a photograph of somebody else's face.
If only the upper teeth are restored, the lower teeth become the reference that every observer compares them against. Whitening the lower arch at 180 EUR before the shade is taken usually gives a cleaner result than choosing a darker ceramic to meet stained lower teeth halfway. Ceramic does not respond to whitening afterwards, so the order matters: whiten first, wait two weeks for the shade to stabilise, then decide the ceramic.
A camera flash is a hard, direct light that raises apparent brightness and flattens the subtle translucency that makes a tooth look real. If flash photographs matter to you, say so before the shade is fixed and we will choose half a shade lower.
Only within narrow limits. Surface staining and glazing can darken or characterise a crown slightly; making it brighter is not realistic. Meaningful change means remaking the units, which is exactly why the daylight check before cementation exists.