Table 2.

Critical Markers of Color Change According to the National Bureau Standards (NBS)

NBS Unit Definitions of Color Differences
0.0–0.5 Trace extremely slight change
0.5–1.5 Slight slight change
1.5–3.0 Noticeable perceivable change
3.0–6.0 Appreciable marked change
6.0–12.0 Much extremely marked change
12.0+ Very much change to other color