The aim of this study was to determine the influence of different layering thicknesses of composite resin on chroma and value. Three enamel-shade VITA-based composite resins (Filtek Supreme Ultra Enamel [SPUE], Durafill VS [DFVS], and Estelite Omega Enamel [EOE]) and one body-shade VITA-based composite resin (Filtek Supreme Ultra Body [SPUB]) with different percentages of filler by volume were investigated (shade A1). Specimens of 0.5-, 1.0-, 1.5-, and 2.0-mm thickness and 10-mm diameter were fabricated (n = 3). Optical properties and VITA Classical shade were measured with a spectrophotometer. Chroma (C*ab) and value (*L) were determined. To determine the influence of thickness on the optical parameters, Pearson correlations between thickness and chroma and between thickness and value were calculated. Two-way analysis of variance was computed for all composite resins (α = .05). Chroma increased as the thickness increased (r = 0.465), whereas the value decreased (r = –0.769). Chroma and value were significantly different among the four composite resins (P < .0001). The highest chroma was observed for DFVS, whereas the lowest chroma was found for SPUE. The highest value was found for SPUE, whereas the lowest value was found for EOE and SPUB. VITA shade remained unchanged for SPUE and SPUB, irrespective of the thickness. The increase in thickness changed the basic VITA shade for DFVS and EOE after 1.5 mm. Increasing the thickness of the enamel layer results in increased chroma and decreased value. Enamel layers should be restricted to a maximum thickness of 1.0 mm. (Am J Esthet Dent 2011;1:158–168.)