Delta-E      DeltaE   deltaE   Delta - E

Normally calculated from CIELAB, which is a colour space based on how the average human perceives colour, created by Commission Internationale De L'Eclairage or International Commission on Illumination announced in 1976.

Delta-E is a measurement used to indicate the difference between two colours. The higher the dE value, the further away the two colours are from one another.

Typically the smallest difference the average human eye (standard observer) can detect is 1.0 dE, but it is worth noting that the human eye is more sensitive to certain ranges of colours than others. For example, a difference of 3.0 dE between two colours in one region of the colour space may not be visible, but the same colour difference in another could well be.

There have been adaptations and refinements of the calculation of Delta-E (CIE76), to factor in perceptual non-uniformities, namely dE (CIE94) and dE (CIE2000), but this calculator is based on the original CIE76 equation, which in many instances, is still the only accepted one.