What is Delta E or ΔE

Delta E, ΔE or dE, is a way of measuring the visible difference, or error between two colors mathematically. It is handy for sorting the “closeness” of products like paints, plastics, or printed material to a scanned sample and has obvious applications in industrial and commercial quality control.

The LAB color system is used as a base system to calculate Delta E, as the LAB system’s perceptually uniform nature makes these calculations more accurate than in other non-uniform systems such as RGB or CMYK.

To put it simply, the Delta E of two colors is the distance between them in LAB color space. This is also called Delta E 76 or Delta E 1976, as it was first standardized in the year 1976. We now use a more accurate formula that takes into account new and improved models of the human eye, this formula is Delta E 2000. Even though the Delta E 76 formula is still very popular, Nix Sensor Ltd. recommends always using the Delta E 2000 formula for maximum accuracy and excellent real-world results.

Note: A smaller Delta E value represents a better or closer color match. A Delta E of 0 would be interpreted as both colors being exactly/mathematically the same. The Delta E system does not have negative numbers.

Even though a Delta E of 0 between two colors represents a perfect mathematical match, it is possible for two colors to look exactly the same to the human eye with a non-zero Delta E. This is due to the physical limitations of human eyesight. The exact Delta E that colors become indistinguishable from each other is dependent on the industry, surface finish of the material, texture, gloss, and the individual person viewing the color. Typically, though, a just noticeable difference between the two colors is about in the range of Delta E of 1.0 – 2.0.