Objective: To evaluate the influence of in-office bleaching on the color stability of dental restorative materials. Materials and Methods: Forty five discs (n = 15) measure 10 mm in diameter and 2 mm thick were prepared from nanofil composite (Filtek Z350, shade A2). Specimens were bleached as follow group A (Opalescence Boost), group B (Philips dash), and group C (Philips Zoom) according to the manufacturer's instructions. The Commission Internationale de L'Eclairage (CIE 𝐿∗, 𝑎∗, 𝑏∗) system was chosen for image processing. Results: Statistical analysis was performed with one way ANOVA, and student's test with a 𝑃 value of ≤ 0.05. The three bleaching materials showed no significant color changes of (Δ𝐸) with clinical color change. The color parameters (𝐿∗, 𝑎∗, 𝑏∗) showed significant color changes. Conclusions: The bleaching gels had influences on color and whiteness of resin composites which clinically perceived. Clinical Significance: the existing composite restorations will not match the natural tooth color after bleaching, and their replacement may be required.