To What Extent May Color Deviate?

Why Color Tolerance Is Not a Fixed Number — But Depends on Product, Material, and Market

Color is everywhere. Color has a function — and one of those functions is commercial. Products have a specific color that fits within the color scheme. If the right color positively influences purchasing behavior, the opposite also applies.

This makes color differences an important topic: what are color differences? And how large can tolerances be before we reject a product on color quality?

The Theory

Color difference is the distance between two colors in the color space. A unit of color difference may or may not be visually perceptible — that depends on the color region. In the red and yellow part of the color spectrum, we perceive a difference sooner than in the green part.

To measure color differences, there are various instruments:

| Type | What It Measures | | ----------------- | ------------------------------------------------------------------------ | | Spectrophotometer | Spectral reflection → calculates color values in any desired color space | | Tristimulus meter | Direct X, Y, Z values via filters | | Color reader | Simplified color measurement for quick identification |

All these instruments can express color differences in the CIELAB system: difference in lightness (ΔL*), red-green (Δa*), and yellow-blue (Δb*). The total color difference is calculated using the Pythagorean theorem (ΔE*ab) or with more advanced formulas such as ΔE00 (CIEDE2000).

The Practice

That's the theory. In practice, the question "how much may color deviate?" depends on more than formulas and measured values. Three factors determine the allowable tolerance:

1. The Type of Product

Visible color deviations in composite products are often not desirable. A color difference in the customer's perception detracts from quality — and thus has a negative consequence for sales.

On the other hand: when a customer accepts a visual color difference, you can question how much effort you should put into matching colors. Sometimes the investment in time is not worth it.

But note: color differences also have unconscious influence. Put five composite products next to each other and one of them has a perceptible color difference — that product is the first to be eliminated.

2. The Material

In some cases, the influence of the material is so great that color differences will almost always exist. Think of natural products such as concrete, wood, textiles, or ceramics.

An example: SNKI carried out an assignment for a municipality, where we were asked to establish a color bandwidth for the restoration of concrete slabs on an event square. The capriciousness of a material like concrete makes it complicated to determine color tolerance in the regular way — standard ΔE limits are not sufficient.

In such cases, a customized approach is needed: reference measurement, statistical spread, and a tolerance framework that fits the material.

3. The Market

Tolerances differ by industry — and sometimes drastically.

| Industry | Typical Tolerance | Special Consideration | | ------------------------- | ------------------------- | ---------------------------------------------------------- | | Automotive | Very tight (ΔE < 0.5–1.0) | Metamerism control under multiple light sources | | Coatings / powder coating | Tight (ΔE 1.0–2.0) | Depends on gloss and texture | | Textiles | Medium (ΔE 1.0–3.0) | Depends on material and dyeing process | | Construction / concrete | Wide (visual, CUR scale) | Material capriciousness makes tight tolerances unrealistic | | Food / packaging | Variable | Product dependent, often visually assessed |

A specific example from the automotive industry: color differences after damage repair. This often involves illuminant metamerism — two panels that appear identical under one light source but differ under another light source. Therefore, color matches in this industry are always assessed under multiple light sources. Tolerances are rarely accepted here.

It's Up to the Specialist

Whether color may deviate depends on multiple factors. It is up to the color specialist and color maker to professionally establish the tolerance — based on the product, the material, the market, and the expectation of the end user.

A good tolerance framework prevents two things: unnecessarily rejecting acceptable products and incorrectly approving products that do not visually meet standards.

---

👉 Want to learn more about color tolerances and quality control? View the courses at kleurenschool.nl

---

Questions about color tolerances or color measurement? Contact the specialists at the Netherlands Color Institute: https://kleurinstituut.nl/contact