This study was performed to evaluate effect on color and opacity of 3 different copy-milled In-Ceram cores by glass infiltration and porcelain veneering. Color was evaluated by the $CIEL^*a^*b^*$ readings were recorded with a Colorimeter, Color difference value(${Delta}E^*_{ab}$) was calculated and opacity was represented by the contrast ratio. The variance of each color parameter ($L^*,;a^*,;b^*$), color difference value, and opacity change after glass-infiltrated and after veneered with porcelain was compared. Three experimental groups were fabricated as follows. Group 1 (Alumina core) 15 Alumina blanks was infiltrated with originally marketed glass (A1) and veneered with porcelain(A1) Group 2 (modified Alumina core) : 15 Alumina blanks was infiltrated with its associated glass(S11) and veneered with porcelain(A1) Group 3 (Spinell core) : 15 Spinell blanks was infiltrated with originally developed glass(S11) and veneered with porcelain(A1). The results were as follows: 1. After glass infiltration, $L^*$ value showed decrease, $a^*$ value showed decrease only group 1(p<0.001) and $b^*$ value showed increase on group 1, increase on group 2, 3(p<0.001). 2. After porcelain veneering, $L^*$ value showed decrease(p<0.001), $a^*$ value showed increase on group 1, decrease on group 2(p<0.05) and $b^*$ value showed decrease on group 1, increase on group 2, 3 (p<0.001). 3. ${Delta}E^*_{ab}$ between before and after glass infiltration was more than 13.77, and between after glass infiltration and after porcelain veneering more than 19.63. 4. After glass infiltration and porcelain veneering, Alumina showed the lowest $L^*,;a^*$ value and highest $b^*$ value among 3 different groups (p<0.05). ${Delta}E^*_{ab}$ between group 1-2, 1-3 was higher than that of group 2-3. 5. After glass infiltration, opacity showed decrease, Group 1 had the highest opacity(p<0.05), but no significant differences between group 2 and 3. Above results suggest that glass infiltration and porcelain veneering effects on color and opacity of In-Ceram core, and that modified In-Ceram Alumina uses single crowns or bridges like In-Ceram Spinell.