ISO 8654 is the international standard published by the International Organization for Standardization that establishes the gold colour designations for jewellery alloys. The standard prescribes a system for classifying gold-alloy colours by reference to standardised colour samples, allowing manufacturers, retailers, and consumers across markets to communicate consistently about gold colour despite the underlying complexity of multi-component gold-alloy compositions.

Background

Gold jewellery alloys vary widely in composition. The major colour-determining metals alloyed with gold are silver (which moves the colour towards greenish), copper (which moves the colour towards reddish), nickel or palladium (which whiten), and zinc and small amounts of other metals (which adjust working and casting properties). The same fineness, say 18 karat at 750 parts per thousand, can therefore present in colours ranging from green-yellow through warm yellow to red-rose, depending on the proportions of silver and copper, and through to white when nickel or palladium dominates the master alloy.

The colour designation system

ISO 8654 defines a system of colour designations referenced to standardised colour samples, typically labelled with two-character alphanumeric codes. The system covers the principal gold-alloy colours encountered in jewellery: yellow, red, pink, green, and white in their characteristic shades. Each designation is anchored to a master colour sample held by the standards bodies and reproducible by referenced colorimetric measurements (CIE L*a*b* coordinates or equivalent) so that a designation in one country corresponds to the same colour as the same designation in another.

The standard's purpose is not to prescribe alloy compositions but to standardise the colour vocabulary. A 14 karat rose gold made in Italy, the United States, and China may have somewhat different copper-silver proportions, but if all three are designated under the same ISO 8654 colour code, they should be visually equivalent within the tolerance of the standard.

Use in the trade

Major jewellery manufacturers and design houses use ISO 8654 designations in their catalogues, technical specifications, and supplier communications. Retail tags increasingly carry colour names aligned with ISO 8654 vocabulary, providing the consumer with a meaningful indication of colour beyond the bare karat designation. Bespoke and custom makers reference ISO 8654 colour samples when matching a customer-supplied antique piece for restoration or for new jewellery to complement an existing set.

Related standards

ISO 8654 is part of the ISO 174 jewellery standards portfolio that includes ISO 9202 on fineness designations, the assay method standards (ISO 11210, 11426, 11427), and the disclosure standards (ISO 18323, 24016). The full set of standards governs the description, verification, and labelling of jewellery materials in international commerce. ISO 8654 is revised at intervals as colorimetric technology and trade practice evolve, and the current version available from ISO or the relevant national standards body should be consulted for the authoritative text.