Table 4.

Trichromatic coordinates of the cotton knit treated with TiO₂-1% Fe-N (Samples 1 and 2), stained with 0.01 g/L methylene blue (MB) and coffee exposed to visible light (Xenotest).

Sample	L*	a*	b*	dL*	da*	db*	dE*	dC*	dH*	Grades
Control cotton knit stained with MB	86.98	−2.06	−2.53	0.23	5.62	5.14	7.62	−7.59	0.61	2
Cotton knit ITO-MB	82.32	−3.83	−7.02	2.46	1.04	1.23	2.94	−1.58	0.30	3.50
HT1-MB	84.75	−4.32	−2.93	5.48	13.37	9.68	17.39	−16.5	−0.25	1
HT1 ITO-MB	90.35	−2.01	−0.34	13.31	14.66	13.27	23.84	−19.48	−3.39	1
HT2-MB	82.13	−6.05	−5.68	2.07	11.82	7.59	14.2	−13.96	1.57	1
HT2 ITO-MB	89.68	−3.07	−1.47	5.92	14.92	10.49	2.2	−18.2	−1.2	1
Control cotton knit stained with coffee	80.26	4.96	19.72	3.46	−0.68	0.45	3.56	0.26	0.77	3
Cotton knit ITO-coffee	71.95	6.86	22.17	1.82	−0.72	−2.42	3.12	−2.53	−0.03	3.50
HT1-coffee	78.38	5.2	21.92	5.06	−0.91	0.6	5.18	22.18	-	2.5
HT1 ITO-coffee	82.25	4.99	22.61	4.88	−1.33	0.68	5.1	0.34	1.46	2.5
HT2-coffee	81.29	5.25	23.69	4.05	−1.16	0.6	4.25	0.3	1.27	2.5
HT2 ITO-coffee	80.98	5.56	25.26	2.9	−0.67	1.54	3.35	1.34	1.01	3