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Between the history of color and associations with certain shades in different cultures, color meanings and usage are fascinating to learn about. Here are 10 fun facts about colors.

1. Blue Was Once Seen as a Low-Class Color

In Ancient Rome, royalty wore white, red and black. Those in lower society wore blue. Because the color blue was associated with the working class and barbarians, it was not mainstream. Blue became more acceptable when it became the color of the Virgin Mary’s cloak in the 12th century.

2. Queen Victoria Started the White Wedding Gown Tradition

In 1840, red was the popular color of bridal gowns. Queen Victoria didn’t follow this tradition, wearing a white gown to her wedding instead. Within a few years, white wedding dresses were regarded as the best color for brides.

3. Some Languages Describe Colors and Shades Differently

Tribal African tongues and other languages describe blue and green as different shades of the same color. The Russian language specifies light and dark blue as different colors, not different shades of the same color. Many ancient languages didn’t have a word for blue.

4. Purple Was the Color of Royalty Because It Was Expensive to Obtain

Until 1856, the color purple came from snail mucus. The snails used were almost extinct, and 20,000 were required to get one ounce of purple dye. Since purple was a rare and expensive color, it was only worn by royalty. For commoners, wearing purple was a crime punishable by death.

5. Red Is the First Color a Baby Sees

Infants start to recognize the color red at two weeks old because red has the longest wavelength, which is easy to process. Babies can see the full spectrum of colors at five months.

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.

The changing chocolate marketplace is raising the bar for quality and opening up opportunities for experimentation. Image Source: Pexels user Kaboompics

Late last month, chocolate lovers received welcome news: a new study published in Heart revealed that chocolate reduces the risk of developing atrial fibrillation, a common form of heart arrhythmia.1 By examining data from the Danish Diet, Cancer and Healthy study, researchers found that people who consumed 1-3 servings of chocolate once a month had a 10% lower rate of new atrial fibrillation diagnosis than those who ate less than one serving a month. What’s more, the rate of diagnosis reduced “17% for one weekly serving, 20% for two to six weekly servings, and 14% for one or additional daily servings.”[“Chocolate May Reduce Risk of Developing Common Heart Arrhythmia”, May 24, 2017, Forbes]

These findings add to a growing body of research suggesting that chocolate has the potential to protect cardiovascular health. Although most research thus far has focused on dark chocolate, the new study included both dark and milk chocolate. This follows data published in 2015 indicating that any type of chocolate reduces the risk of heart disease.2  And while doctors aren’t entirely sure why chocolate appears to benefit heart health, but they do have guesses. As Dr. Howard LeWine, chief medical editor of Harvard Health Publications, says, “It may be related to flavonoids, a type of antioxidant produced by plants. Flavonoids have been shown to help lower blood pressure, improve blood flow to the brain and heart, and fight cell damage.”3

This new recognition of the health benefits of chocolate also has clear benefits for the chocolate industry, allowing for new product and marketing opportunities and changing the way the public perceives sweet treats. Dark chocolate is already outpacing milk in terms of growth, attributed largely to growing awareness of its impact on cardiovascular health. But Katrina Markoff of artisan chocolatier Vosges Chocolate believes there’s more to the story. “Dark chocolate has health benefits and that is a source of appeal, but I also believe people’s palettes are really becoming more sophisticated,” she says. “There is more awareness and curiosity about milk and dark and even different specific varietals.”4 Indeed, the high-end chocolate market has exploded in recent years, spurring major players like Nestle to develop premium offerings while also opening up the door for a niche bean-to-bar industry.

In this changing environment, there is more pressure on both industry old-timers and newcomers to produce chocolates of the highest quality. At the same time, public acceptance of new and novel products means there is also plenty of room for experimentation. And whether you are refining traditional treats or inventing new concoctions, measuring the color of chocolate is now more important than ever before.

The color of chocolate gives consumers important clues about taste and quality. Image Source: Pexels user Pixabay

USDA/AMS is the most general source for visual color standards for fruits and vegetables and offers a catalogue of color comparators and equipment they have available.

USDA Equipment Catalog for Fresh and Processed Products Inspections is available on the internet Agricultural Marketing Service and provided through:

Processed Products Branch

Fruit and Vegetable Division, AMS

U.S. Department of Agriculture

P.O. Box 96456, Rm. 0709, So. Bldg.

Washington, D.C. 20090-6456

www.ams.usda.gov

USDA Visual Color Standards and other equipment related to fruits and vegetables can be ordered from:

Equipment & Forms Depot

USDA, AMS, FVP, SCI

831 Mitten Road, Room 200

Burlingame, CA 94010 USA

+650-552-9073

FVSupplyDepot@ams.usda.gov