Top: evolution in the HRD of the 0.8 M_⊙ models for 16 different Y_ini between 0.248 and 0.8 (Z = 5 × 10^-4). Colors depict the evolutionary phases (main sequence in black, subgiant and red giant branch in magenta, central helium burning in blue, post central helium burning in red; the pre-main sequence is not shown for clarity). Bottom: 0.8 M_⊙ models computed with Y_ini = 0.248, 0.4, and 0.8 (black, red, and green, respectively).