Color values were measured with a color meter (CR-200, Minolta Co., Tokyo, Japan). Data was expressed by Hunter L (lightness), a (redness) and b (yellowness) and ΔE value was calculated with the following equation
Color values were measured with a color meter (CR-200,Minolta Co., Tokyo, Japan). Data was expressed by HunterL (lightness), a (redness) and b (yellowness) and ΔEvalue was calculated with the following equation