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The human eye can perceive millions of colors, but it does not always distinguish them accurately. Two slightly different colors may appear the same, or identical colors may look different depending on viewing angle and lighting. This creates challenges when communicating about color. For designers and manufacturers, the inability to precisely identify and communicate color complicates efforts to replicate standards and detect discrepancies.

To reproduce an exact color consistently, manufacturers and designers rely on ways to quantify a color's properties and calculate the numerical difference between colors. CIELAB, or CIE L*a*b*, is a device-independent, three-dimensional color space that measures and compares all perceptible colors using three values. In this space, numerical differences correspond to the degree of change humans can perceive.

CIELAB is based on opponent color theory showing that the brain interprets retinal inputs as differences between light and dark (lightness) and between opposing pairs of colors: red/green and blue/yellow. This is known as the principle of color opposition correlation, as a color cannot be both red and green, or yellow and blue, simultaneously. For example, you will never see a "greenish red.

What Is the CIELAB Color Model?

The L, a, b color space was first defined in 1942 by Richard S. Hunter, founder of HunterLab. Hunter’s system used coordinates labeled L, a, and b, calculated from the CIE 1931 XYZ color space, and was intended to be more perceptually uniform. In 1976, the International Commission on Illumination (CIE) created the CIELAB model as a refinement of Hunter’s work. To distinguish between the two systems, CIELAB uses L*, a*, b* notation. The “CIE” refers to the French name of the organization: Commission Internationale de l'Éclairage.

Both Hunter L, a, b and CIELAB (L*, a*, b*) are grounded in Opponent-Color Theory, which assumes that the human eye perceives colors in opposing pairs:

• L scale: Light vs. dark, with low numbers (0–50) indicating dark and high numbers (51–100) indicating light.
• a scale: Red vs. green, with positive values indicating red and negative values indicating green.
• b scale: Yellow vs. blue, with positive values indicating yellow and negative values indicating blue.

An ideal color scale would be uniform, meaning that a one-unit difference would appear visually equal regardless of hue. In practice, neither Hunter L, a, b nor CIELAB is perfectly uniform. Hunter’s scale applies a square root function to Y/Yn for calculating lightness (L), which tends to compress values in the yellow region and expand them in the blue region. CIELAB, by contrast, applies a cube root function to X/Xn, Y/Yn, and Z/Zn, with a linear extension near black. While this improves uniformity overall, CIELAB tends to over-expand the yellow region of color space. Both scales are effective for measurement and for setting tolerance standards. However, CIELAB generally provides a closer match to visual perception. With practice, either system supports intuitive understanding and communication of color values.

What if your next plant-based drink could achieve stunning golden color—naturally, consistently, and without compromising shelf life? That vision just moved closer to reality.

A peer-reviewed study in Food Frontiers reveals how a one-step pH infusion of raw turmeric into soymilk delivered reliable, vibrant color. Using the HunterLab ColorFlex EZ spectrophotometer, researchers tracked L*, a*, b* values to evaluate and confirm the consistency of this natural process.

Please note: the ColorFlex EZ has now been upgraded to the ColorFlex L2. For a seamless transition and added benefits, you’ll find more details in the second half of this blog.

Key Findings from the Study

This study offers compelling evidence for a practical, clean-label solution:

• 94% curcumin transfer from raw turmeric into soymilk, with stable particle size and charge
• Both curcumin–soymilk and turmeric–soymilk showed b* increases above 40 units versus plain soymilk, creating a distinct golden-yellow hue
• Both freeze-dried curcumin–soymilk and turmeric–soymilk powders remained stable over a 30-day storage period at freezing temperature.

These results highlight how tristimulus color measurement enables effective monitoring of natural pigment integration across product lifecycles. More importantly, they demonstrate a path to achieving natural color in plant-based milk—a key priority for brands focused on clean-label innovation.

Why It Matters to HunterLab Customers

For Plant-Based Beverage Producers

The study provides a scalable route to functional pigment delivery. Use ColorFlex L2 to maintain color consistency across shelf life with simple benchtop quality control.

For Turmeric and Spice Processors

Validate raw turmeric batches without requiring purified extracts. ColorFlex L2 readings enable quick grading and premium positioning for buyers.

For Nutraceutical Brands

Support label claims of protein and curcumin co-delivery. Tristimulus color data confirm dose uniformity in ready-to-mix formulations.

For Food Science R&D Teams

Leverage a peer-reviewed protocol pairing pH encapsulation with tristimulus tracking. Reproduce or expand for other botanicals.

For Quality Labs and Co-Packers

Color shift is a primary indicator of curcumin degradation. Use ColorFlex L2 for quick pass/fail metrics before packaging.

Export buyers notice inconsistencies—do you? Manufacturers often rely on ground samples and handheld chroma meters. This method fails to capture whole-nut appearance. A roast-level measurement that aligns with consumer expectations can elevate product consistency—especially for global export markets.

A slightly over- or under-roasted cashew can affect perceived quality, flavor, and brand trust. Yet many processors still rely on outdated, destructive color checks that don’t reflect what the consumer sees.

Let’s fix that.

Why Color Accuracy Drives Cashew Quality

• Consumer confidence: Global buyers expect golden-brown uniformity. Irregular batches erode trust.
• Export readiness: Color variation is a top rejection reason for U.S. and EU-bound shipments.
• Flavor & texture proxy: Roast color is linked to browning index and sensory qualities.

The Problem with Ground Sample Methods

1. Inaccurate representation: Grinding mixes inner and outer nut layers, masking true surface color.
2. Prep variability: Operator technique affects grind consistency and packing.
3. Low throughput: Each test can take 8–10 minutes—including warm-up, grind, and tray prep.
4. Wasteful: Ground samples can’t be reused—costing time and raw materials.

Clarity is a critical aspect of liquid product quality in many industries, and modern consumers combine it with color when evaluating whether to buy a product or trust a brand. As a result, scientifically and objectively quantifying haze is essential to achieving quality goals and maintaining customer satisfaction.

What Is Haze and How Does It Alter the Appearance of Liquids?

In its simplest definition, haze is scattering of light produced by small particles in a sample. Suspended particles within a liquid also scatter light, leading to turbidity — a cloudy, milky, or opaque appearance.

Transmission haze occurs in transparent goods and liquids, like clear plastic preforms or bottled water. As light passes through the sample, factors like surface texture imperfections and impurities scatter the energy.

Primary Causes of Haze in Liquids

In liquids, a natural interaction between proteins and polyphenols usually causes measurable turbidity. Other potential causes include poor-quality raw ingredients, such as infected barley used in beer brewing or particulate residues from filtering processes.

The Importance of Haze to Consumer Perceptions

Clarity is necessary in liquids to signify quality and safety.

Turbidity in beer can be either desirable or undesirable, depending on the consumer's preference. Many manufacturers continually aim to control turbidity in beer since its presence can negatively impact taste and shorten shelf life. Others use turbidity as a competitive advantage, crafting hazy IPAs that consumers perceive as more flavorful. Similarly, some winemakers prefer haze as a marker of authenticity and a natural by-product of fermentation.

Other liquids also rely on haze to meet consumer expectations or generate a favorable customer opinion. For example, a haze in fruit juices can spur more sales by promoting the perception that nutritional value is higher. Manufacturers can create the haze naturally or use additives to produce the intended result.

Consistent quality and aesthetics are paramount in the competitive world of building materials. For vinyl siding manufacturers, achieving consistent color across production batches is crucial for customer satisfaction and brand reputation. 

Here at HunterLab, we offer state-of-the-art spectrophotometers, advanced quality control software and expert techniques to help you maintain color consistency throughout your vinyl siding production processes.

Understanding the Challenges of Measuring the Color of Vinyl Siding 

Even slight color variations can lead to rejections, returns, and lost revenue. Visually assessing vinyl siding is not enough to achieve accurate, repeatable results and can lead to mismatched siding panels.

Measuring the color of vinyl siding presents unique challenges compared to other materials. Some of these challenges include:

• Texture variations: Vinyl siding often has a textured surface that can affect light interaction. HunterLab's spectrophotometers have advanced features that can compensate for surface texture variations. They ensure accurate readings regardless of the siding's texture.
• Large panel sizes: Larger panels magnify any variation in the manufacturing process, from raw material differences to pigment distribution and alterations occurring in storage. A spectrophotometer accurately quantifies color at every stage to help ensure consistent, precise results.

Because most bath bombs contain multiple colors, you need to use a color measurement system to ensure that the colors match and remain vibrant. Image Source: Pixabay user StockSnap

A bright fuschia bath bomb hits the water and immediately starts to froth. Long streams of pink, purple, and red leak into the water, coating the top of the bathtub in a thick layer of colorful bubbles. But as the bath bomb dissolves and shrinks, unexpected colors begin to appear, from deep blues to rich emerald greens. This surprise pop of color is what draws thousands of customers to bath bombs every year.

Unlike traditional bath salts and soaps, which are usually just one color, bath bombs can contain as many as a dozen different layers of color in a single package. For cosmetics manufacturers, this poses a challenge: how do you ensure that these colors will look appealing to customers, both before and after they hit the water? To solve this issue, you need an accurate color measurement system for your bath bombs and multi-colored soaks.

You’ll Need to Measure Color Twice

When you’re working with large batches of any commercial product, you need to ensure that your colors are consistent batch-to-batch. But a color measurement system for bath bombs has to measure more than just consistency of each ingredient; it also needs to measure how the colors interact with water and with the other colors in the mix. For instance, if you add too many similar-looking colorants into a bath soak, you will likely end up with a product that looks muddy rather than multi-colored. Similarly, even if your bath bomb looks perfect when it’s dry, its colors might not mix well together in the water or could be duller in appearance than you expected.
Without testing how your colors mix together in water, you might accidentally release a product that looks brown in tone after customers put it in the water. This is a common problem when making bath bombs because companies often like to mix a primary color with its complementary color, causing the mix to turn brown.1 However, you can counteract this if you use colorants that can’t interact with one another in water or if you carefully measure the colors you use to ensure that their final blend is an appealing new color. By measuring your colors twice (once during the dry, powdered stage, and again as a dissolved liquid sample), you guarantee that your bath bombs will look equally beautiful on the shelf as they do in the tub.

Some natural bath bombs and soaks contain solid materials or colorants that are less saturated than standard dyes. Image Source: Pixabay user Tomasz_Mikolajczyk

Essential oil spectrophotometers help you determine how pure an oil is based on its color, which in turn could impact how your perfume smells. Image Source: Flickr user sunny mama

The alluring aroma of a perfume might win over the heart of a picky customer, but experienced perfume manufacturers know that this is only one small part of what makes a particular scent so enticing. In reality, the perfume’s color also plays a major role in sales, and in some cases, can directly impact the scent of the perfume itself. After all, the quality of a perfume is only as good as the ingredients that went into producing it. If you want to ensure that the oils you use are absolutely pure and powerfully fragrant, you should consider investing in a spectrophotometer. Using this tool, you can make sure that each bottle of perfume looks identical and that you’re always using the best essential oils available.

• Some essential oils, like sandalwood, will look darker in color and appear hazier than clear, brighter essential oils like lavender. Image Source: Flickr user Your Best Digs