For people who work in color management, the term delta E probably has come up many times. However, most people would wonder, what is delta E?
Delta E is a unit of measurement for color difference perceived by humans. The E stands for Empfindung; German for “sensation”. The scale goes from 0 to 100 with 0 meaning no color difference and 100 being the greatest color difference possible. Delta E has evolved quite a bit over the last four decades. It started as a simple mathematical calculation to later a calculation that incorporates adjustments to account for variations in a human’s ability to perceive color differences in different color regions. In the most modern delta E standards (delta E CMC, 2000), a delta E of less than 1.0 is not perceivable by most humans. People who either have superior color vision or have received specific training can perceive color differences down to 0.6 delta E.
What do all of these numbers mean? Well, lets see it visually:
How do you perceive and adjust for color differences?