From: Impact of nanohydroxyapatite on enamel surface roughness and color change after orthodontic debonding
Color parameter
Definition
Color range
L*
Measure of lightness (value)
Ranging from black (0) to white (100)
a*
The position on red-green axis
Ranging from red (+) to green (−)
b*
The position on yellow-blue axis
Ranging from yellow (+) to blue (−)