Effect of metallicity on the SED. The initial model (red line) is the fifth model of the 60 M_⊙ series at Z = 1/30 Z_⊙. The blue line shows the same model for which the metallicity has been changed to 1/5 Z_⊙, all other parameters being kept constant. In the model shown by the orange line, in addition to metallicity, the mass-loss rate has been increased by a factor 4.2 according to Ṁ ∝ Z^0.8. Finally, in the model shown in green, the mass-loss rate has been reduced down to log Ṁ = −7.30. The H I, He I, and He II ionizing edges are indicated by vertical black lines.