Our conversion tool uses the CIE Delta-E 2000 (CIEDE2000) algorithm, the gold standard for perceptual colour difference measurement. Here is how it works:
- Colour Space Conversion: Both the source and target colours are converted from their native colour space (RGB, CMYK, etc.) into CIE L*a*b*, a perceptually uniform colour space.
- Delta-E Calculation: The CIEDE2000 formula computes the perceived difference between the two L*a*b* values, accounting for lightness, chroma and hue weighting factors.
- Ranking: All colours in the target system are compared, and the closest matches (lowest Delta-E) are returned.
- Quality Rating: Delta-E below 1.0 = Exact (imperceptible difference), 1.0-3.0 = Close (minor difference), above 3.0 = Approximate (noticeable difference).
This approach is more accurate than simple Euclidean distance in RGB space, because RGB is not perceptually uniform. Two colours that are far apart in RGB values may look similar to the human eye, and vice versa.