Spectral energy distributions modeled at nine different times during the evolution of stripped stars. The displayed models are for stars with initial masses of 8.15 (top), 12.17 (middle), and 18.17 M_⊙ (bottom). The spectral models are created during the helium core burning at the time when the stripped stars have central helium mass fractions of X_He, c = 0.9, 0.8, ...0.1, which we highlight using purple, pink, and yellow colors. We use blue colors to mark the parts of the spectra that are H I-, He I-, and He II-ionizing. The spectral models are very similar during the stripped phases for the three stars, with the exception of the uncertain He II-ionizing part of the spectrum.