There is no universal value; tolerance is agreed in writing between customer and dyehouse. In normal commercial practice ΔE CMC (2:1) around 1.0 is common, sometimes up to 1.5 for difficult shades. Dark colours, neon and highly saturated shades struggle with tight limits.
What matters is what is being compared: the production lot against the approved lab dip, or against the previous lot. Agree in advance the formula, the illuminant (D65), the measuring method and what happens if a lot falls outside tolerance. A vague agreement causes disputes at delivery, especially on reorders.



