Numerical value that represents the distance between two colors in the Lab color space. This formula was introduced in 1976 and is therefore also known as Delta E 1976.

In many cases, a delta E of 1.0 is the smallest color difference the human eye can see. Unfortunately it’s not that simple. Some color differences greater than 1 are perfectly acceptable, maybe even unnoticeable. Also, the same delta E color difference between two yellows and two blues may not look like the same difference to the eye.