Objectives To evaluate the optical influence of core build-up composites on the resultant color of ceramic–composite combinations, and analyze the color difference of ceramic–composite combinations to Vita Lumin shade guide with the same nominal shade. Methods Thirty ceramic specimens, with a standardized thickness, were made from three all-ceramic materials (Empress2, In-Ceram, Vita Mark 2). Nominal shades A1 and A3 of the Vita Lumin shade guide were selected. Fifty disc-shaped composite specimens were fabricated using ten colors of core build-up composites. The combinations of ceramic and resin specimens were used to simulate the all-ceramic restorations. The colors of the combinations and A1/A3 shade tabs were measured with a spectrophotometer. The results were converted to CIE L * a * b * and CIE L * C * H * values, then color differences (Δ E) and translucency parameters (TP) were calculated for each combination and ceramic material. Mean Δ E values were analyzed with three-way ANOVA and Turkey's multiple comparison tests were used to evaluate the within-group effect of the shades of the composites. The corrections between the Δ Es and TPs were evaluated using a linear analysis. Results Color differences were significantly influenced by the composite shade, ceramic system, and ceramic shade ( P < 0.001). Mean color differences were 7.023, 8.290, and 6.347 for In-Ceram, Empress2 and Mark2 system, respectively. Δ E values were significantly associated with the TP values. Significance The color of underlying core composite has a significantly influence on the resultant color of an all-ceramic restoration. The use of the Vita Lumin shade guide does not accurately achieve the intended color duplication.