India permits a small, defined list of synthetic food colours but
"permitted" is category-specific. A dye allowed in a soft drink or a
confectionery isn't automatically allowed in tea. When a lab tests a tea
sample, it isn't checking whether these colours are under some limit
it's checking that they're absent altogether. Here are the seven most
commonly tested for, and where they're actually meant to be used instead.
Sunset Yellow FCF
An orange-yellow dye, one of the most frequently found where it shouldn't be, precisely because its shade sits close to the natural colour of brewed tea. We've written a full explainer on this one specifically.
Tartrazine
A lemon-yellow dye, widely used in soft drink mixes, confectionery, and custard powders. Along with Sunset Yellow, it's one of the two most common synthetic yellows in the Indian food supply which also makes it one of the first things worth checking for in any product where a bright, uniform yellow-orange colour is doing some of the visual work.
Ponceau 4R
A red dye used in products like jellies and processed seafood. In a reddish-brown drink like tea, a colour like this could be used to deepen or standardise the shade of a weak brew.
Carmoisine
Another red synthetic dye, chemically related in function to Ponceau 4R, used across confectionery and beverages. Same category of concern: cheap, stable, and capable of making a weak product look stronger than it is.
Erythrosine
A pink-red dye, historically used in confectionery and some cherry products. Less commonly implicated in tea specifically, but part of the standard colour panel because it's on the permitted list for other foods.
Indigo Carmine (Indigotine)
A blue dye. On its own it wouldn't suit tea, but blue dyes are sometimes used in small amounts in combination with yellows and reds to fine-tune a final shade which is exactly why a full panel, not just the obvious suspects, is worth testing.
Fast Green FCF
A green synthetic dye, permitted for a narrow set of uses elsewhere. Included in a full colour panel for the same reason as Indigo Carmine: completeness, not because it's the likely culprit.
Brilliant Blue FCF
Another blue synthetic dye, widely used in beverages and confectionery where it is permitted. As with Indigo Carmine, its relevance to tea testing is about ruling out the full combination space, not a specific suspicion.
Why test for all seven, not just the obvious one
Colour additives are rarely used alone a manufacturer trying to hit a specific shade may blend two or three dyes rather than use one at a heavy concentration. Testing only for the colour named in a public complaint would miss that. A full panel is the only way to actually rule out added colour, rather than just rule out one dye.
Where our tea stands
Batch 12 of New Fast Tea was tested for all seven of these colours at an NABL-accredited laboratory. All seven came back Not Detected.
Read the full Batch 12 report → See every batch we've tested →
A note on completeness: this panel of seven does not include every synthetic colour that exists, and we've been explicit elsewhere about where our own testing still has gaps.