What is a jump light?

 

Imagine two color swatches that appear to match under D65 illumination but exhibit a noticeable color difference under TL84 illumination—this is Metamerism, also known as color constancy. The MI (Metamerism Index) is a key metric for quantifying this phenomenon, reflecting the degree of color variation under different light sources. The higher the MI value, the greater the risk of lamp jumping. 。

 

 

And the dye's Color constancy It should also not be overlooked, as it reflects the stability of a dye’s color under different light sources. It is important to note that “color shift” refers to the contrast in how two colors change under different lighting conditions, whereas “color constancy” pertains to the degree of color variation for a single color.

 

Why does the light flicker?

 

Why does the light flicker? The primary cause is dye discoloration. If the reference sample and the comparison sample use the same dye, the color verification process becomes remarkably straightforward. Under these circumstances, human color assessment rarely gives rise to disagreement. Once the issue of dye-induced color change is resolved, the influence of material-induced color change and observer-induced color change will both be significantly reduced.

 

The author once heard at a Zhejiang dyeing and printing factory that paper color cards are “extremely popular”—because of the differences in material, these factories have considerable leeway in negotiations. In fact, during the L/D sample confirmation stage for colors, competition becomes less objective due to the varying dyes used by different dyeing plants.

 

Example of Observer Color Change

 

Because When color shift occurs, the maximum error between human eyes can reach DE1.5. However, when spectrophotometers are made from different materials, even with color-matching and color-difference algorithms designed to keep color differences within 0.8, reliable performance can be difficult to guarantee. Consequently, many dyeing mills opt for manual color matching when the DE value is 0.8. This, in turn, necessitates a prerequisite: whether an MI flash occurs. If no flash occurs, both the spectrophotometer and the human eye achieve a high success rate in color matching.

Color Index dye index issuing authority

 

As for the jump-light issue, The root cause lies in the color chart. Currently, most color charts on the market are influenced by dye manufacturers: instead of using dyes with International Color Index (CI) numbers, they incorporate other dyes that are prone to color shift under lighting, leading to supply-chain disruptions. For instance, when annual color charts from many well-known U.S. sportswear brands are processed at dyeing facilities in Taiwan, China, the high cost of dyes often results in weeks of unsuccessful sampling and repeated revisions before a final approval can be obtained.

 

 

Within the brand and throughout the supply chain, Color charts come in a wide variety and often involve color matching across different materials. There is a lack of effective in-house inspection tools at the garment and fabric stages, and dyeing and finishing mills sometimes fail to match colors against approved samples; in some cases, dyes are even changed without retaining L/D samples, making it difficult to trace color-matching discrepancies. In the absence of color-viewing cabinets and spectrophotometers, workshop personnel can only rely on subjective judgment when adjusting colors, which inevitably increases the risk of color deviation.

 

Color-related issues have grown increasingly complex due to the fine-grained division of labor, to the point where they have even become trade secrets. Over the past two decades, these problems have not only failed to improve—they have, in fact, grown more severe.

 

How to predict lamp flickering?

How can one accurately predict color shifts under lighting? While color-matching light booths are a commonly used solution, they have obvious drawbacks. The lamp tubes used in these booths are manufactured to inconsistent specifications, and some specifications even lack genuine, branded products. Moreover, if the light booth is not used in a darkroom, it will be affected by Interference from Mixed Light Sources . Most importantly, The light box still relies on subjective human judgment. When color-discrimination personnel exhibit sensory insensitivity or face conflicts of interest, their judgments are highly prone to error.

 

A thousand-yuan spectrophotometer can display spectral reflectance.

 

In comparison, a spectrometer is a more reliable choice. Even Even spectrometers in the thousand-yuan price range can effectively predict lamp-flashing phenomena. By analyzing the reflectance curve, we can predict in advance how a color will appear under different light sources, thereby preventing color shift caused by switching lights.

 

Colorless transformation curve

Color-changing curve

 

The Chinese Solution to Addressing Flashing Lights

 

 

To address the challenge of skipped lights, a systematic and comprehensive solution must be developed. China’s DCH color space has emerged. Leveraging a cutting-edge solution that enables rapid color-card production, it is deeply integrated with visual color-difference formulas and equipped with a domestically developed spectrophotometer along with comprehensive, professionally designed training courses.

Just as the 1976 Color Map (GPS) has now been upgraded to the 2025 BeiDou Navigation Satellite System, China’s DCH color space technology likewise provides unprecedentedly precise navigation for color management. We hope that through this technology, Enhancing China’s voice in the global industrial color market and accelerating our overseas market expansion. , steering the course of color management across China’s apparel industry chain.