The electronic structure of CaWO4 crystal containing F-type color centers are studied within the framework of the fully relativistic self-consistent Direc-Slater theory, using a numerically discrete variational (DV-Xα) method. We come to a conclusion that F and F+ color centers exhibit donor energy level located in the forbidden band. The optical transition energies are 1.92eV and 2.42eV, respectively, which correspond to the 650nm and 515nm absorption bands. It is predicted that the 650nm and 515nm absorption bands originate from the F and F+ centers in CaWO4 crystals.