Table 2. Color change class

Class	Color difference	Color change effect
1	△E < 0.2	Invisible changes
2	0.2 < △E < 2.0	Very small changes
3	2.0 < △E < 3.0	Small changes (color changes visible by high-quality filter)
4	3.0 < △E < 6.0	Medium (color changes visible by medium-quality filter)
5	6.0 < △E < 12	Big (distinct color changes)
6	△E > 12	Different color

Adapted from Hrčková et al. (2018) with permission of NC State University.
Adapted from HunterLab (2012) with permission of Hunter Associates Laboratory.