Table 1.

The results of the color changes of the standard samples and the aging samples.

Sample	L	A	B	L	A	B	ΔL	ΔA	ΔB	ΔE
	Standard Sample			After Aging			Results
Orange pigment	56.82	15.08	23.72	52.99	17.79	25.38	−3.83	2.71	1.66	4.98
Calcite	90.65	0.77	8.85	87.29	0.82	12.95	−3.36	0.05	4.1	5.3
Hematite	38.02	12.95	11.42	32.16	12.35	11.30	−5.86	−0.6	−0.12	5.89
Madder	78.62	10.12	12.82	73.13	11.54	14.11	−5.49	1.42	1.29	5.8
Gold layer	76.79	8.38	34.72	71.48	8.08	32.40	−5.31	−0.3	−2.32	5.8
Malachite	55.36	−15.05	16.40	49.98	−17.16	14.89	−5.38	−2.11	−1.51	5.97
Magnetite	28.85	−0.16	3.60	20.79	1.37	3.79	−8.06	1.53	0.19	8.2
Orpiment	72.60	12.91	50.24	64.93	10.06	48.24	−7.67	−2.85	−2	8.4
Egyptian blue	50.48	−6.41	−6.28	35.84	−6.05	−5.80	−14.64	0.36	0.48	14.65