This calculator computes the color difference between a sample color and a reference color. Both colors are expressed as CIELAB. If you have colors in some other form (e.g. XYZ), you may use the CIE Color Calculator to convert them to Lab for use with this color difference calculator.
The color differences are computed in several different ways:
| CIE 1976 | This is the standard CIE color difference method, which is simply the distance between the two colors, calculated in three-dimensional Lab color space. |
| CIE 1994 | This is a more recent modification which has been recommended by CIE TC1-29 as the CIE94 color difference formula. For graphic arts applications, K1 = 0.045 and K2 = 0.015. For textile applications, K1 = 0.048 and K2 = 0.014. |
| CIE 2000 | This is a even more recent modification. In this implementation KL = KC = KH = 1.0. |
| CMC (1:1) | This method is drafted to become a new ISO standard (ISO 105-J03). This implementation uses a lightness weight of 1.0 and a chroma weight of 1.0 for use with perceptibility data. |
| CMC (2:1) | As above, but using a lightness weight of 2.0 and a chroma weight of 1.0 for use with acceptability data. |
Note that for some of the Delta E methods, the color differences are not symmetric (CIE 1994 and 2000). That is, the difference between Color A and Color B may not be the same as the difference between Color B and Color A. In such cases, one color must be understood to be the reference or standard against which a sample color is compared.