Variator

A tolerance written as “ΔE00 3” is one number for many different colours. The Variator shows them: eight variants around the aim, each exactly the chosen ΔE00 away, in eight directions of the a*b* plane.

How the wheel is built

Every segment is solved numerically so that its CIEDE2000 distance from the aim equals the number in the selector — not a Lab offset, a real ΔE. Opposite segments are therefore twice that apart. The centre disc is the aim. Five wheels exist for the lightness of the variants, and the dots under the wheel switch between them:

WheelL* weight against a*b*Middle
lighter1 : 1ring = aim, small disc = pure +L
a little lighter0.3 : 1disc = aim
same lightness0 : 1disc = aim
a little darker−0.3 : 1disc = aim
darker−1 : 1ring = aim, small disc = pure −L

What to look for

The same ΔE is not the same visibility. A step towards yellow reads smaller than the same step towards blue; a lightness step reads larger than either. Turn the wheel through its five lightnesses and the 3 ΔE that seemed generous in one direction becomes obvious in another. That is the argument for a tolerance per axis — see Snowflake.

The construction is the one CC Capture prints on its Variator sheet: eight compass directions per wheel, five lightness classes, separators in the paper colour.

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