Delta E
Delta E (ΔE) is a number that measures how different two colours look, where 0 means identical and a larger number means a bigger visible difference.
This encyclopedia calculates ΔE with CIEDE2000, the colour-difference formula published by the International Commission on Illumination (CIE). It compares two colours’ lightness, chroma and hue, weighted to match how people perceive differences.
As a rough guide, a ΔE of about 1 is close to the smallest difference most people notice when two colours sit side by side. The site labels matches as follows: up to 2.0 is virtually identical, up to 3.5 near-identical, up to 5.0 very close and up to 8.0 similar. Close matches and dupes are limited to a ΔE of 5.0 or less.
ΔE compares colour values only. Two lipsticks with a ΔE near zero can still look different on the lips if one is matte and the other is a gloss, and screens, lighting and skin all change how a shade reads. ΔE is the number behind every dupe and every comparison on this site.
Last verified . How we measure.