The aim of this study was to investigate color matching under natural daylight and daylight lamp conditions. Twenty-nine preclinical students underwent a training course and then matched randomly chosen shade tabs of Vita 3D-Master Shade Guide under both natural daylight and daylight lamp conditions. Color difference (Delta E_ab) between presented and selected shade tabs was calculated. Statistical differences were explored by use of multivariate analyses. Mean Delta E_ab was 2.5(1.0 to 4.3) with daylight lamp and 3.4 (0.9 to 7.4) with natural daylight. The difference was statistically significant (P < .001). The use of a daylight lamp helps to standardize light conditions and significantly improve the ability to match colors. Int J Prosthodont 2009;22:75–77.