2.4.2. Color
Without grinding, the color values of raw and extruded DCF
were measured by using a Colorimeter (Minolta JP/CR-300, Japan).
Color values L, a, and b as measures of lightness, redness, and yellowness
respectively were recorded for each sample. The colorimeter
was calibrated against a standard white tile (L ¼ 97.60,
a ¼ 0.19, b ¼ 1.34). Measurements were performed in triplicate.