"Same Colour" Cannot Be Enforced

Colour is the attribute most likely to be argued about and least likely to be defined. A buyer says the tape is too red, the factory says it matches the lab dip, and both are describing a real perception that neither can prove. The clause that follows usually says the colour must match the approved standard "in daylight", which settles nothing, because daylight varies from a north-facing window in Manchester to an afternoon in Guangzhou.

An enforceable shade clause replaces perception with measurement, and measurement with a decision. That means naming an instrument, a geometry, an illuminant, a sample size and a numeric boundary before bulk production begins. None of these choices is difficult; the difficulty is making them early, when nobody is yet angry.

Choose the Instrument Before the Number

A Delta E value without a measurement condition is not a specification. The same tape can read differently under different geometries, apertures and illuminants, and the differences are large enough to move a lot from pass to fail. Decide the following, in this order, and write each one into the clause.

  1. Instrument type. A spectrophotometer, not a colourimeter, if you need to communicate values between factories.
  2. Geometry. 45/0 or integrating sphere, stated explicitly; the two are not interchangeable.
  3. Illuminant and observer. D65 with the 10 degree observer is the common default for textile work.
  4. Aperture. Large enough to cover the tape pattern; 10 mm is typical, 4 mm for narrow tape.
  5. Measurement position. Specify where on the tape, how many readings, and whether the average or the worst reading governs.
  6. Colour difference formula. Name it, because Delta E 2000 and Delta E 1976 give different numbers for the same pair.
  7. Standard reference. A physical standard kept by both parties, measured at the same time as the submission.

Clause Block

CLAUSE 9 - SHADE AND COLOUR TOLERANCE
9.1 Reference: approved physical standard 26-0417,
    signed and retained by both parties on 2026-02-14.
9.2 Instrument: spectrophotometer, 45/0 geometry,
    D65 illuminant, 10 degree observer, 10 mm aperture.
9.3 Measurement: 5 readings per lot, tape relaxed and
    flat, average of readings governs.
9.4 Acceptance: Delta E 2000 (CIE) shall not exceed 1.0
    against the reference. Readings between 0.8 and 1.0
    require Buyer's written concession before shipment.
9.5 Lot uniformity: maximum Delta E 0.5 between the
    first and last metre of any single dye lot.
9.6 Metamerism: a pair that matches under D65 but
    exceeds Delta E 1.5 under A shall be rejected.
9.7 Light fastness: minimum grade 4 at 20 AFU,
    ISO 105-B02.
9.8 Responsibility: Seller measures and reports at
    shipment; Buyer verifies within 3 working days of
    arrival. The Buyer's reading governs where the two
    differ by more than 0.3.

Measurement Protocol That Both Sides Can Repeat

  • Condition samples for 24 hours at 20 degrees Celsius and 65 percent relative humidity before reading.
  • Fold the tape to at least four layers so the aperture sees only tape, not the backing or the table.
  • Take readings at both ends and the middle of the piece; record all of them, not just the average.
  • Re-measure the physical standard on the same day; a drifted instrument invalidates every reading taken with it.
  • Keep the raw data with the lot number, the operator and the instrument serial number.

The protocol is not bureaucracy. It is what allows a third party to reproduce the result six months later, which is the only thing that ends a colour argument permanently.

What Happens at the Boundary

The most useful sentence in a shade clause is the one that describes the grey zone. A hard limit of 1.0 with no intermediate step turns a 1.02 reading into a rejected lot and a cancelled order, which is rarely what either party wants. A two-tier structure works better: readings up to 1.0 pass automatically, readings between 1.0 and 1.3 may be accepted by written concession with a price adjustment or a scheduled replacement, and readings above 1.3 are rejected outright.

Pair the tiers with time limits. A concession decision should be made within two working days of the reading, and a replacement should have a committed ship date before the concession is signed. Otherwise the concession becomes a way of accepting a problem without solving it.

For programmes where shade consistency across a garment matters more than absolute accuracy, add a lot-to-lot clause. Donglong applies a 0.5 Delta E limit between consecutive dye lots on the same article, because a customer comparing two jackets on a rail sees the difference between lots long before they see a difference from the standard.

Whatever structure you choose, name the zones: pass, concession, reject. A clause with three named bands is read the same way by a dye house in one country and an inspector in another, which is the entire point of putting it in writing rather than agreeing it on a call.

A Note on Use

This article is general commercial and technical reference, not legal advice. Colour tolerances must be set against the actual material, the end use and the capability of the dye house, and the clause should be reviewed by qualified counsel before it is incorporated into a contract.