Objective: The study investigates the effects of modeling liquids (MLs) on the staining of composite resins, with a focus on unichromatic resins. Materials and methods: The research was carried out by subjecting samples of monochromatic resin (2mm height x 6mm internal diameter) to the immersion protocol in coffee solution (Nescafé Tradição Forte), with color evaluation after 21 days. Results: Statistics showed that the adhesive group presented greater color change when compared to the modeling group (p = .000). There was no statistically significant difference between water and experimental staining (= 0.104). Among the staining group factors, there was a difference for ∆E in the interactions mC-mE (p = 0.004), mC-aC (p < 0.001), mC-aE (p < 0.001), cE-aC (p = 0.015), cE-aE (p = 0.007), cC-aC (p = 0.033) and cC-aE (p = 0.017). Conclusion: These results indicate the need for further clinical studies on the applicability of modeling liquids to support decision-making in clinical practice.