Analysed models shown as coloured dots on the spectroscopic HR diagram (sHRD) with the colour representing the value of Γ_max in each model. The Eddington factor Γ_e (assuming electron scattering opacity only) is directly proportional to the quantity L and is indicated on the right Y-axis for a hydrogen mass fraction of X = 0.74. Some representative evolutionary tracks of non-rotating models, for different initial masses (indicated along the tracks in units of solar mass), are also shown with solid black lines. The green and blue dotted horizontal lines correspond to Γ_e = 0.7 for X = 0.7 and X = 0, respectively. The colour palette and the models marked with yellow diamonds correspond to those in Fig. 2. The black dashed line roughly divides the sHRD into distinct regions with Γ_max> 1 and Γ_max< 1.