HRD for the STAREVOL models on the main sequence. The most evolved tracks (150 and 200 M_⊙) are shown up to a central hydrogen mass fraction equal to 0.015. The evolution of the surface helium mass fraction is colour-coded on the tracks. The left panel shows the tracks obtained using the new mass-loss recipe by Gräfener (2021), and the right panel shows those using the old mass-loss recipe combining Vink et al. (2001) and Nugis & Lamers (2000), as in Martins & Palacios (2017). The evolutionary points at which atmosphere models and synthetic spectra have been computed are indicated with squares..