Top panel: mass-to-light ratio M_⋆/L_i as a function of the rest-frame colour g − i for the 76642 ALHAMBRA galaxies with F814W ≤ 23 at z < 1.5. The coloured lines show level contours in the density of galaxies, starting at 0.1 galaxies dex⁻² and increasing in 1.5 galaxies dex⁻² steps. Red contours show the quiescent population, and blue contours the star-forming one. The side panels show the normalised distribution in g − i (upper panel) and log₁₀ (M_⋆/L_i) (right panel). In both panels the total distribution is presented in black, the quiescent population in filled red, and the star-forming population in filled blue. The black dashed line marks the relation derived by Taylor et al. (2011) at z < 0.65 using GAMA galaxies and SDSS five-band photometry. Bottom panel: comparison between the observed ALHAMBRA mass-to-light ratio and that expected from the Taylor et al. (2011) relation. The red solid line is the best Gaussian fit with median ⟨ΔΥ⟩ = 0.01 dex and dispersion σ_ΔΥ = 0.10 dex.