Fluororubber (FKM) has an important application in the industrial field. However, the coloring problem of FKM has always affected the performance of its mechanical properties. Herein, a novel silicon dioxide (SiO2) colored with acid orange 7 (AO7) was prepared by sol-gel method to ameliorate the mechanical properties and coloring property of FKM. Acid orange silica sol was prepared by adding AO7 to sodium silicate solution, and then colored SiO2-AO7 was prepared by freeze drying. The effects of SiO2-AO7 modified FKM on mechanical properties, thermal conductivity and coloring were systematically studied. The results show that SiO2-AO7 has the advantage of enhancing the mechanical properties of FKM without affecting its color appearance. Relative to the unmodified FKM, the tensile strength and modulus at 300% elongation saw enhancements of 47.2% and 21.8% respectively. The SiO2-AO7 offers exceptional coloration and mechanical reinforcement, showing strong suitability for industrial application.