The four contributors
Colour in a tea liquor comes from four broad sources. The flavonol glycosides and related compounds present in the leaf give the pale yellows and greenish-yellows of an unoxidised tea. Chlorophyll and its breakdown products contribute to the appearance of the leaf and to a lesser extent to a green liquor. The theaflavins, formed early in oxidation, are orange-red and give a good black tea the bright coppery quality that professional evaluation looks for. And the thearubigins, the larger and later products of continued oxidation, are brown and account for the bulk of the depth of colour in most black tea. Add to these the fine suspended material a liquor carries, which affects clarity rather than hue, and the account is essentially complete. The important structural point is that all four are compositional signatures — they report what the leaf was made into, not how much of it is in the water — which is why the rest of this page is about the difference between those two questions.
Why colour tracks processing rather than strength
A dark liquor indicates how far oxidation ran, and a pale one indicates that it did not run far. Neither says anything about how much material is dissolved. A pale gyokuro brewed at a high leaf ratio can be far more intense in the mouth than a much darker supermarket black tea, and a very dark cup from a broken grade may be mostly colour with comparatively little else. This is the mechanism behind one of the most persistent brewing errors, which is judging when to stop by looking. It also explains a common disappointment with green tea specifically: a drinker who expects a green tea to look like tea and finds a pale yellow cup concludes it is weak and steeps it longer, which extracts the astringent fraction and produces exactly the harsh cup that confirms their suspicion. The reliable measures of strength are the dose, the time and the taste, and the catalogue records brewing parameters by mass and volume rather than by any visual endpoint for precisely this reason.
Chlorophyll, and the visible signal in green tea
The one place where colour is a genuinely reliable indicator, and it is about the leaf rather than the liquor. The bright green of a well-made green tea comes largely from chlorophyll, which is chemically fragile: under heat, light and acidic conditions it converts to a related olive-brown compound, the same change that dulls green vegetables when overcooked. So a green tea or a matcha that has shifted from vivid green towards khaki has undergone it, and the shift tracks the loss of freshness closely enough to be used as a proxy. Matcha shows it most clearly, being the one tea whose condition can be judged reliably by eye before brewing. Two cautions apply. The comparison has to be against the same tea when it was new rather than against an ideal, since a later-picked or less thoroughly shaded leaf is duller when fresh. And the liquor version of the check requires a freshly poured cup, since a standing green liquor dulls visibly within an hour on its own.
Brightness and clarity, which are separate from hue
Professional black tea evaluation distinguishes brightness — the clear, luminous quality of a good liquor as against a dull or muddy one — from colour, and scores it as an independent criterion. Brightness is associated with the theaflavins and with a well-run oxidation stopped at the right point, and it is visible before anything is tasted; a well-made black tea in a white cup shows a coppery ring at the edge that tasters read routinely. Clarity is a third thing again and is largely mechanical, depending on how much fine suspended material the liquor carries, which is a function of leaf grade, filtering and pouring. A deep-steamed Japanese tea is cloudy by construction and is not less clear in the evaluative sense; a broken tea through a coarse strainer is cloudy for a different reason. Reading hue, brightness and clarity as three separate observations rather than as one impression of colour is what turns looking at a cup from a guess into evidence.
Haze, and what it means
A strong black tea goes cloudy as it cools, and the cause is a specific and rather elegant piece of chemistry: caffeine and the larger oxidation products form complexes that remain in solution while hot and come out of it as the liquor cools, producing the haze the trade calls cream. It is associated with a liquor rich in exactly the compounds a good black tea should have, so it is closer to a quality signal than a defect, and it is the direct cause of cloudy iced tea. The remedies address the cooling rather than the tea: chill quickly, brew at double strength over ice so the drop is fast, or brew cold from the start so the complexes never form, and a little acid clears an existing haze. None of these improves the drink. A different kind of cloudiness comes from suspended particles rather than from complexes, is present from the moment of pouring rather than appearing on cooling, and points at leaf grade and filtering — distinguishing the two is a matter of when the cloudiness arrived.
Reading a liquor honestly
Colour tells you what kind of tea you have and roughly how it was made: pale yellow-green for an unoxidised tea, deepening yellows and light ambers through the oolong range, orange-red and coppery for a well-made black tea, dark brown to nearly opaque for a dark tea. It tells you about condition in green teas specifically, where a shift towards olive is a real signal. It does not tell you strength, it does not tell you quality, and it does not tell you when to stop steeping. The general position the catalogue takes is to record liquor colour as a descriptive field on a tea alongside the sensory axes rather than as a proxy for anything, and to keep brewing guidance in terms of mass, volume, temperature and time. Anyone who has been brewing by eye and switches to brewing by dose and clock generally finds that several teas they thought they knew were being systematically over- or under-extracted, and the green teas most of all.