Elastomer blends exhibit enhanced mechanical properties, but understanding the viscoelastic material characteristics is challenging. For pure elastomers, standardized methods for the characterization of the frequency-dependent material behavior exist. Typically, dynamic-mechanical-thermal-analysis (DMTA) and the time-temperature superposition principle are applied. However, the latter is not feasible for immiscible blends. Therefore, a novel approach based on the microstructure of filled blends and the well-known viscoelastic properties of pure elastomers is presented. The homogenization framework is put to the test for carbon black-filled blends of Natural Rubber (NR) and Styrene-Butadiene Rubber (SBR). It is implemented into an in-house finite element (FE) code, starting from image processing of atomic force microscopy (AFM) and considering the inhomogeneous filler distribution. The simulation results are master curves of storage and loss moduli in the frequency domain.