Best-fit intrinsic alignment amplitude of NLA fits to w_g+ measurements from the different galaxy sub-samples, plotted against their average luminosity logarithm. The red or n_s>2.5 galaxy samples (red circles and orange triangles, respectively) are split into five luminosity bins, while the galaxy samples selected on both colour and n_s (brown star or square) are not split in luminosity. A power-law luminosity-dependent A_IA is fitted to the intrinsically red and n_s>2.5 samples, plotted as red and orange solid lines, respectively, with the colour band indicating 1-σ intervals of the best-fit parameters.