What Is Color Measurement? — Understanding and Measuring Color Accurately

What Is Color?

Color is perceived through the interaction of three elements: the light source, the object, and the observer. When light strikes an object, some wavelengths are absorbed while others are reflected. The reflected light reaches the observer’s eyes, and the brain interprets it as color. Together, these three elements determine how color is perceived.

Light source: Without light, color cannot be perceived. Color appearance changes depending on the type of light source, such as daylight, fluorescent lighting, or LED lighting.
Object: The color of an object is determined by the wavelengths of light that its surface selectively reflects and absorbs. A red apple, for example, appears red because it reflects red light while absorbing most other wavelengths.
Observer: The way the human eye and brain perceive color also affects color appearance. The same color may appear different depending on age, individual visual characteristics, and differences in color vision.

太陽からの光（白色光）と反射光

Color appearance changes depending on the light source, object, and observer. For example, the same white shirt may appear white in daylight but slightly yellow under an indoor lamp. This is because different light sources have different color temperatures and spectral power distributions.

Similarly, the same shade of red may appear different on paper and plastic because the materials reflect light differently, affecting their perceived texture and brightness. Color perception also varies according to the observer’s visual characteristics. Individual differences in color vision may make certain colors more difficult to distinguish.

Because color appearance is influenced by many factors, it is important to quantify color through measurement rather than relying solely on visual evaluation. Color measurement enables consistent evaluation by standardizing the light source and viewing conditions and managing color as objective data.

Color and Color Appearance

An individual color can be described by the spectral characteristics and physical properties of light. Color appearance, on the other hand, is created by combinations of multiple colors and by the way those colors are perceived under specific viewing conditions. Most objects in the real world do not consist of a single, uniform color. Instead, they contain combinations of colors, subtle variations, and gradients.

Even within the general category of “blue,” for example, the blue of the sky and the blue of the sea create different impressions. Subtle differences arise from their surroundings, textures, and the way they reflect light. This is because color appearance involves more than a simple collection of colors; it is also influenced by visual, psychological, and cultural factors.

PaPaLaB focuses on color appearance because the colors encountered in the real world are rarely completely uniform. In product finishes and design, subtle color differences, variations, and combinations can significantly affect perceived quality. We therefore believe that accurately measuring and inspecting color across an entire surface is essential.

空の「青」と海の「青」

Color Measurement and Inspection

Color appearance is not simply a collection of individual colors. It is shaped by light, materials, and human vision. Effective color management therefore requires objective color measurement rather than reliance on visual evaluation alone. Appropriate inspection criteria and procedures are also needed to ensure that measurement results are used effectively in quality control.

Proper color measurement and inspection help ensure color consistency and reproducibility, making it possible to maintain stable product quality.

Methods for Measuring Color

Various measurement methods are used to evaluate color objectively.

Spectrophotometric Measurement:
A method that separates light into individual wavelengths to measure the color of an object accurately. It is suitable for detailed color analysis at a specific point.

Color Difference Measurement (ΔE):
A method that compares a sample with a reference color and expresses the difference numerically as Delta E (ΔE). It is used to monitor variations in product color and maintain consistent quality.

2D Color Measurement:
A method that records the distribution of color across a surface as an image and analyzes characteristics such as color unevenness and gradients. It captures color information over a wide area rather than at a single point.

Conducting appropriate inspections based on measured color data makes it possible to maintain consistent product quality. In product inspection, for example, the color uniformity of painted or printed surfaces can be evaluated to reduce variation and ensure stable quality.

In the food and beverage industry, color is managed as an important quality indicator. Products are inspected to ensure that their appearance reflects the expected freshness and quality. Preventing color differences that may make a product appear inconsistent or undesirable is also important.

In the fashion and design industries, the colors of fabrics and cosmetics must be managed to confirm that the intended colors have been reproduced accurately.

By combining appropriate color measurement with inspection, color can be evaluated more accurately, enabling more reliable quality control based on objective color data.

2次元色彩測定イメージ：(左)検査例　(右上)検査品全体　(右下)色分布

関連ページ：色彩とビジネスへの影響