Short answer
There is no universal acceptable ΔE. A tolerance is an agreement about a specific formula, measurement condition, reference and product — and it has to be wider than the measurement uncertainty to be enforceable. Contract proofs under ISO 12647-7 allow averages of 2.5 ΔE00; textiles have long used CMC 2:1 with a pass limit agreed per customer; rules of thumb such as 'ΔE00 below 1 is invisible, below 2 is close' are useful starting points, not standards.
A number like '2.0' specifies nothing on its own. A usable tolerance states the formula (ΔE00, CMC 2:1, ΔE*ab), the illuminant and observer (D50/2° for print, often D65/10° for paint and textiles), the geometry and specular mode, the measurement condition for fluorescent materials, the physical reference and how it is kept, and whether the limit applies to single readings, averages or a percentile. Often it also limits components separately — a lightness limit and a hue limit — because customers accept a slightly darker batch more readily than a slightly greener one. Omit any of these and two parties can measure the same sample, both correctly, and disagree.
Printing is unusual in having international numeric tolerances. ISO 12647-7:2016 gives contract proofs 3.0 ΔE00 on paper white and solids, an average of 2.5 and a maximum of 5.0 across the control strip, and 2.5 on spot-colour solids, and states that tolerances below 2.5 ΔE00 are impractical between instruments of different models. Production printing standards set their own tolerances around the same aims. These are a useful benchmark for what careful, standardised industrial colour reproduction achieves — roughly, averages of a couple of ΔE00 units — rather than a threshold of visibility.
Textiles have used CMC(l:c) since the 1980s, usually at 2:1 so that lightness differences, which buyers tolerate more, count half as much. The pass limit is agreed per customer and product: tighter for plain dyed fabrics sold in sets, looser for fashion prints. Paint and plastics suppliers commonly use ΔE00 or CMC with separate limits on lightness and on metamerism between illuminants. In all three, a tolerance zone shaped like the formula's ellipsoid — narrow in hue, wider in chroma and lightness — accepts more of what customers accept than a sphere of the same size.
Colourwise's own guidance for its tools is that a CIEDE2000 difference below about 1 is unlikely to be noticed, 1 to 2 is visible on close side-by-side inspection, and above about 2 is visible at a glance. That is a reasonable reading of the formula's design but it is editorial: it assumes large, adjacent, flat samples under good light. Separated by a gap, seen minutes apart, or on textured materials, much bigger differences go unnoticed; on large side-by-side panels such as car-body parts, smaller ones are rejected. Set tolerances from visual assessment of real borderline samples, then measure them — not the other way round.
| Field | Usual formula | Typical conditions | Where the limit comes from |
|---|---|---|---|
| Contract proofs | ΔE00 | D50, 2°, 45°/0°, M1 | ISO 12647-7:2016 (e.g. average ≤ 2.5) |
| Offset production | ΔE00 or ΔE*ab per edition | D50, 2°, 45°/0° | ISO 12647-2 and customer agreement |
| Textiles | CMC 2:1 | Often D65, 10°, sphere | Agreed per customer and product |
| Paint and plastics | ΔE00 or CMC, with component limits | Often D65, 10°, sphere SCI/SCE | Agreed per specification, with metamerism check |
| Colourwise tools (guide only) | ΔE00 | Computed from sRGB/CIELAB values | Editorial: < 1 hard to see, > 2 visible at a glance |
Why: The difference is concentrated in hue, which viewers notice more than the single ΔE reflects, or the pair is metameric under store light.
Fix: Add a component (hue) limit and a secondary-illuminant check to the specification.
Why: The limit is below the agreement between the two parties' instruments.
Fix: Set limits above measured inter-instrument agreement, or use one shared instrument.
Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.
StandardStrong evidence
ISO 12647-7:2016 sets contract-proof tolerances of 3.0 ΔE00 for paper and process solids, an average of 2.5 and maximum of 5.0 ΔE00 across control-strip patches, and 2.5 ΔE00 for spot-colour solids.
Source: ISO 12647-7:2016 … — Part 7: Proofing processes working directly from digital data
ConventionModerate evidence
The CMC(l:c) formula is used in textiles with l:c commonly set to 2:1 for acceptability decisions.
Caveat: Pass limits themselves are set per customer and product; there is no single CMC limit.
Source: Modification to the JPC79 colour-difference formula; Color difference (Wikipedia)
Colourwise interpretationLimited evidence
As a working guide, CIEDE2000 differences below about 1 are unlikely to be noticed, 1–2 are visible on close side-by-side inspection, and above about 2 are visible at a glance, for large adjacent flat samples under good light.
Based on: Colourwise's reading of the CIEDE2000 scale's design intent and of industrial practice such as ISO 12647-7's 2.5 ΔE00 average; not a published perceptibility threshold.
Caveat: Visibility depends strongly on sample size, separation, texture, colour region and observer.
StandardStrong evidence
Tolerances tighter than the agreement between the parties' instruments cannot be reliably enforced; ISO 12647-7:2016 cites poor inter-model agreement as the reason ΔE00 tolerances below 2.5 are impractical.
Source: ISO 12647-7:2016 … — Part 7: Proofing processes working directly from digital data
Reviewed 29 September 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.