Three different situations, one loose vocabulary
Non-green tea leaves arise in at least three distinct ways. Some cultivars produce shoots that are pale to nearly white in cool spring conditions and green up as the weather warms — a temperature-sensitive deficiency of chlorophyll in the young leaf. Some produce persistently yellow-green shoots, generally described as a light-sensitive rather than a temperature-sensitive condition. And some accumulate anthocyanin pigments, which are red-purple and are present in addition to chlorophyll rather than instead of it, giving a leaf that reads as purple or reddish while still functioning. The first two are deficiencies; the third is an accumulation. Lumping them together as coloured tea plants obscures the fact that a white-leaf cultivar is a weak plant and a purple-leaf cultivar is not. The vocabulary makes it worse by reusing the words white, yellow and purple, each of which already denotes a processing category or a market term in tea, and none of which means the same thing when applied to a leaf on a bush.
Anji Bai Cha, and the confusion built into its name
The most commercially significant of these plants is the cultivar behind Anji Bai Cha, recorded in this catalogue as Bai Ye Yi Hao. In cool early spring its new shoots emerge pale, almost jade-white with green veins, and as temperatures rise the leaves green up and the phenomenon ends for the year — which is why the picking window is short and the tea expensive. The tea made from it is a green tea, pan-fired or otherwise fixed like any other green tea. It is not a white tea, despite bai cha meaning white tea in every other context in the Chinese tea vocabulary. This is a name collision of exactly the kind this guide set keeps flagging: two established meanings, one phrase, no signposting. A drinker who orders Anji Bai Cha expecting something like Bai Mudan will get a fresh, sweet, notably low-astringency green tea instead, and a shop that files it under white tea has made a filing error that a great many shops make.
The yellow-leaf cultivars, and the same problem again
Yellow-leaf cultivars such as Huang Jin Ya produce persistently yellow-green shoots and are grown for a sweet, low-astringency green tea with a strikingly bright appearance. And once again the name collides: yellow tea is an established processing category, defined by a controlled damp-heat yellowing step after fixation, and Junshan Yinzhen and Huoshan Huangya belong to it. A green tea made from a yellow-leaved cultivar is not a yellow tea. It is a green tea from a plant with a pigment deficiency, and it is possible to have either without the other. This matters more than a naming quibble because yellow tea is a genuinely endangered category with very few producers, and having its name applied to an unrelated and much easier product does not help it. TeaHQ keeps the processing categories and the cultivar colours in separate fields for this reason: one is a fact about manufacture, the other is a fact about the plant, and neither implies the other.
Purple: three programmes, one trait
Anthocyanin-rich tea plants have been developed independently in at least three places. Yunnan produced Zi Juan, a bred purple cultivar; Kenya’s research organisation released TRFK 306/1, the basis of the country’s purple tea; and Japan released Sunrouge. Yunnan separately harvests scattered purple-budded plants out of its seed-grown populations as zi ya, which is a landrace phenomenon rather than a cultivar — the distinction between zi ya and Zi Juan is a real one that the market frequently blurs. Purple tea is not a seventh category. The leaf is processed as a green tea or as a black tea like any other, and the colour is a breeding outcome that survives into the dry leaf and, to varying degrees, into the cup, where acidity shifts it towards pink. TeaHQ records the pigment as a compositional fact about the leaf and makes no claim whatsoever about what drinking it does for anybody, which is a discipline the marketing of purple tea has generally not observed.
Why the plants are weak, and what that costs
Chlorophyll is how a plant converts light into the sugars it lives on, so a shoot that is short of it is a shoot that is not paying its way. White- and yellow-leaf cultivars are correspondingly low-yielding, slow, and more demanding to grow than an ordinary green cultivar, and the pale phase in the temperature-sensitive types lasts only as long as the conditions that cause it. That is the mechanical explanation for the price of Anji Bai Cha and its relatives: a short window, a small crop, and a plant that needs looking after. It also has a compositional consequence that is generally reported and worth stating carefully. Pale-leaf material is associated with a higher share of the amino acids linked to savoury sweetness relative to the compounds linked to astringency, which is consistent with the taste of the resulting teas. TeaHQ records the association and does not offer a mechanism, because the published explanations vary and none has been verified here.
How these teas get mis-sold
Three patterns recur. A coloured-leaf tea is filed under the processing category its name resembles, which misleads about what the tea is. A purple tea is sold with claims about the pigment, which is the reason TeaHQ carries a functional-intent layer that cannot make efficacy statements and a health surface that publishes nothing. And an ordinary tea is described as being from a rare white-leaf or purple cultivar, which is unverifiable from the leaf and therefore free to assert. The check available to a buyer is limited but not nothing. These cultivars have short seasons and small planted areas, so a coloured-cultivar tea that is available in quantity all year at a low price is describing something other than what the name implies. And a seller who can say which cultivar, which county and which picking window is in a different position from one who says only that the leaves are purple.