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Color tolerances set acceptable limits for the appearance of a product and are an essential part of quality assurance and quality control processes for color. You can efficiently determine whether a product falls within the limits by establishing tolerances. If it does, the product passes. Failed goods fall outside the tolerances, meaning process adjustments may be necessary to create the desired appearance. 

Many industries, such as food, plastics, and chemicals, rely on accurate appearance. Tolerances enable you to establish a standard and decide how much variation to allow, giving you consistent color outcomes. 

What Is Color Tolerance?

Color tolerances are the parameters within which a product's color can vary yet remain acceptable. Typically, visual assessment is the initial step to define the acceptable color range. Spectrophotometry then objectively and scientifically quantifies and manages those tolerances.

Before establishing tolerance values, you must decide on the observer, choose a color scale, such as Hunter L,a,b, and then select illuminants for comparison, like D 65 and Illuminant A. Depending on what you're measuring, the scale you choose might come from the International Commission on Illumination (CIE), which sets global measurement standards, or from another entity. 

Once you have a comparison standard, you can gather products and measure their color to determine acceptable variations called tolerance values. 

In this process, you start by selecting a relevant standard for your product, then determine how much this standard can vary before it creates visible differences in appearance. This test helps you set boundaries for future production to objectively decide whether products fall close enough to the original standard to conform to quality expectations.

Detecting Color Differences

You can establish tolerances based on two levels of difference:

• Minimum perceptible difference: A visual comparison shows a just-noticeable difference between the standard and the sample. 
• Maximum acceptable difference: The level represents the largest acceptable difference between a standard and a sample. 

Focusing on the maximum acceptable difference means a broader range of acceptable values, while relying solely on minimum perceptible difference can lead to high rejection and material waste. As a result, choosing the right approach is typically industry-driven. For example, the food industry frequently uses the maximum acceptable difference, but pharmaceutical manufacturers usually opt for the minimum perceptible difference.

Range of Tolerance Definition

The range of tolerance is the acceptable level of variation related to an established color standard. You will establish this standard using a measurement model like CIE L*a*b*, which results in three values measuring:

• L*: Lightness, from dark at zero to light at 100.
• a*: Position on the red–green axis, with the positive number indicating red and the negative indicating green.
• b*: Position on the yellow–blue axis, with yellow represented as the positive and blue as the negative.

Once you establish a standard, you can decide on each dimension's tolerance. Here are the formulas for determining the difference (∆) between a sample and a reference:

∆L* = L*sample - L*reference

∆a* = a*sample - a*reference

∆b* = b*sample - b*reference

You can also calculate the total color difference across the three values in a single formula, with the results represented by delta E* (∆E*). Here's the formula to determine ∆E*:

∆E* = √((∆L*)2+(∆a*)2+(∆b*)2)

While ∆E* values can be helpful, use this method carefully. When the difference is spread over three dimensions, you may get a value that looks acceptable but has significant variation in one measurement, such as red vs. green. 

This variation will create a noticeable visual difference but may not impact the delta E* value if the other dimensions are close to the standard. If you calculate the difference values separately, you can more closely monitor each one to verify that none stray too far from the standard.

Vegetable oils such as olive oil and peanut oil must meet consumers' visual expectations with consistent coloring. Vegetable oil manufacturers can please customers and increase profits with color measurement solutions like spectrophotometers.

Among the many challenges facing modern global manufacturers, regulatory compliance ranks at the top. The laws encompass product color standards to uphold consumer safety, advance best practices, and promote standardization. Operations that cross borders also span all these different legal frameworks that cover color and color measurement, from the FDA and USDA to ASTM, ISO, and JIS. Failing to adhere to all applicable standards has real, costly consequences, including material waste, penalties, and fines.

Spectrophotometry is the best solution for ensuring consistent, compliant color measurements. As the universal color translator, these devices provide objective, repeatable data that simultaneously satisfies multiple regulatory frameworks.

Variations in Regional Color Standards and Their Scope

The standards maze goes beyond bureaucratic differences to reflect real industrial priorities and their regulatory enforcement.

Organizations like ASTM and ISO primarily establish measurement methods that instruct manufacturers how to capture readings. For example, ASTM E1164 dictates the geometric conditions required for obtaining spectrophotometric data, such as d/8° or 45°/0°, while ISO 11664 — which is equivalent to CIE standards — defines the fundamental calculations for colorimetry.

In contrast, regulatory bodies like the FDA and USDA rely on these established methods to set the acceptance criteria. For instance, the USDA has specific Color Grades for products like tomato paste and orange juice. Calculating these specific grades requires extracting data using instruments equipped with the correct measurement geometries.

In Japan, Japanese Industrial Standards (JIS) for color measurement align closely with international CIE and ISO principles to ensure global consistency.

As a result, the true challenge for manufacturers isn't documentation and paperwork. It's having the right color measurement solution to bridge these different regulatory frameworks.

The High Costs of Inconsistent Measurement Protocols

Noncompliance with color standards isn't an option. Aside from potential regulatory fines and penalties, violations can lead to:

• Rejection of batches at incoming QC: Customers may turn away entire shipments, essentially doubling shipping costs with return logistics.
• Reworks due to failed color audits: Reformulating, reprocessing, and relabeling products reduces efficiency and profitability.
• Loss of contracts: Manufacturers may face reputational damage and lose future revenue opportunities for failing to deliver to specs and on time.
• Product recalls: If faulty goods hit the market, manufacturers must absorb the costs of recalling the products, which can range into the millions.
• Market exclusion: Repeated violations can result in being banned from selling in certain areas.

Plus, there is a substantial hidden cost to inconsistent measurement protocols — managing separate inventories for different regions. These separate streams mean more variability in raw material colors and less flexibility to redirect products based on demand shifts.

The Pitfalls of Visual Evaluations Across Multisite Operations

Manually evaluating color is an insufficient approach, and one that won't satisfy regulators. The process is unreliable since human color perception varies by individual and observation conditions. Differences in lighting, sample presentation, and operator fatigue will naturally arise, and all can significantly influence the accuracy of your color evaluations.

Visual assessments are also impossible to quantify precisely, so there's no way to document compliance objectively and share that evidence with regulators in other jurisdictions — you can't email a visual impression as proof.

There is no doubt that color affects a consumer's decision when purchasing a product, especially a well-known beverage like cola. Colas from brands such as The Coca-Cola Company and PepsiCo have their signature brown color that few people can mistake for another beverage.

Consumers know what they are looking for when they want a cola soft drink, so it is essential to get the color right when producing these beverages. This blog will explore the famous caramel color of cola and discuss the best practices for measuring the color of these beverages.

Moisture can change the color of fabrics in deliberate, overt ways or create subtle color shifts nearly imperceptible to the human eye. Image Source: Pexels user snapwiresnaps.tumblr.com

The Unseen Emporium in London, England is more of a laboratory than a design house. Through a daring and innovative combination of fashion, chemistry, and digital technologies, the three masterminds behind the label work to produce dynamic clothing, accessories, and lifestyle goods that respond to their environments based on specific stimulants.1 Among their most eye-catching creations are extravagantly tailored leather jackets that change color as the humidity in the room fluctuates, the moisture level creating vivid chromatic shifts. The phenomenon of hydrochromism—color change in response to water—has heretofore primarily been intentionally implemented in the textile industry as a novelty in the form of color-changing umbrellas and swimwear. The Unseen Emporium, however, is bringing it to a new level of artistry.

But hydrochromic textiles are not a recent invention. Although deliberately moisture-sensitive dyes with dramatic color changes may be in their infancy, some level of hydrochromism is inherent to most textiles already in use today, often to the consternation of textile manufacturers.

Dark cotton fabrics will display a greater degree of color change in the presence of moisture. Image Source: Pexels user snapwiresnaps.tumblr.com

Humans have evolved as highly visual creatures, using color as one of the most important signifiers of safety. From a red stop light to a brightly colored snake, color acts as an instant and instinctual visual alarm bell warning us of potential dangers. This use of color as an indicator of safety is perhaps most clearly evidenced by the act of pulling out a piece of fish from the refrigerator and asking, “Does this look okay to you?”

Unlike many color/perception relationships, the one between fish color and food safety is relatively linear; although even experts may not be able to distinguish between white and red wines in blind taste tastes, you can be pretty sure that if a fish looks bad, it is bad. The color change itself is an indicator of a specific sequence of biological events and the process begins almost immediately following death. As Nollet and Foldra point out in the Handbook of Seafood and Seafood Product Analysis:

“The appearance of a newly landed fish is unforgettable, in that the interplay of subtle shades of beautiful colors make it a joy to behold and irresistible as an item of food. Just a few hours after death, though, it begins to look less obviously attractive, and its now ‘ordinary’ colors are much more familiar to the majority of the public.”1

Just as familiar is the look of spoiled fish product: dull, lifeless, decaying, and carrying the potential for food poisoning.

But the determination of fish freshness isn’t just up to individual consumers; the seafood industry as a whole must take great care to assess the quality and safety of products throughout the supply chain, particularly at a time when traceability is a growing concern.

Spectrophotometric instrumentation provide an objective basis for the determination of fish freshness. Image Source: Pexels user Steyn Viljoen

Industries that use raw beeswax need to test the wax for color consistency in order to produce quality products. Image Source: Shutterstock user P-fotography

Raw beeswax is a key ingredient in a wide range of popular products, from lipstick to candles. However, to create products from beeswax, manufacturers have to ensure that the wax is consistent in color and free of impurities. Any variation in color from one batch of beeswax to another could negatively impact the final color of the product.

The primary challenge manufacturers face when working with raw beeswax is that this material is naturally diverse in color; unless the manufacturer consistently sources its beeswax from the same bee farm and controls every aspect of the farm’s environment, the color of beeswax can range anywhere from pale yellow to deep orange in color. To achieve color consistency in their products, manufacturers must, therefore, have strict color quality control protocols in place when using raw beeswax as an ingredient. By testing wax using a spectrophotometer, you can significantly improve the consistency of your products and achieve reliable color results.

The Challenges of Testing Beeswax for Color Consistency

The primary reason beeswax is such a challenging ingredient to work with is that a number of environmental factors can impact the color of the wax.1 All beeswax is white when bees first create it. However, it doesn’t remain this color over time; as the bees gather nectar from neighboring flowers, pollen and propolis (resin from the bark of trees) get stuck to their legs and bodies. This material latches onto the white honeycomb, causing the honeycomb to turn yellow. The darker the pollen and propolis are in a region, the darker the resulting beeswax is.

This is why many manufacturers that use beeswax source their wax from the same farm or from the same general region of the world. The bees in the area are gathering nectar from the same types of flora, so the wax they produce appears roughly the same color. For example, Burt’s Bees sources all of its wax from four farms in East Africa, and as a result, the wax is mostly consistent from batch to batch.2 Additionally, most bee farms in Africa don’t use pesticides and have very little air pollution, both of which can alter the natural color of beeswax. This is why many manufacturers choose to work with African beeswax, as it is considered the purest in the industry.

However, even if you source your wax from the same high-quality farm, there’s no guarantee that your wax will be completely consistent in color. Factors like weather and available food sources on the farm could cause color variations even in wax produced by the same population of bees. For example, if flowers with dark-colored pollen aren’t yet blooming due to poor weather, the bees will produce wax that is much lighter than usual.

This is a problem for your products because it will make them appear inconsistent. In cosmetics products, in particular, customers expect to find the same color and texture every time; if a customer has a favorite red lipstick, any variation in this color will reduce customer satisfaction. Beeswax that’s too dark in color could make a red lipstick appear brown and muddy, and this will negatively impact the customer’s perception of the product.3 This is why, to ensure color consistency, you must test for variations in color between all of your raw beeswax shipments and filter out impurities in the raw wax until it adheres to color standards.

A spectrophotometer that has a large sample platform can measure a greater amount of solid beeswax compared to a spectrophotometer with a smaller platform. Image Source: Max Pixel