An alternative term for the deep-blue artificial colourants known as indigo carmine — the disodium salt of indigotin disulfonic acid used in beverages, sweets, and dessert mixes. Regulatory listings may use either name, so label readers and formulators should recognize both when checking colourant permissions and limits. Because the two terms describe the identical compound, specifications for purity and permitted uses apply equally whichever name appears on the label or in the regulation. Colour suppliers provide it in standardized strengths for consistent formulation.