J. Trayford, T. Theuns, R. Bower, R. Crain, C. Lagos, M. Schaller, and J. Schaye. (2016)cite arxiv:1601.07907Comment: 15 pages, 10 figures. Submitted to MNRAS. All comments welcome. Larger version of Fig. 1 included in source. For the animated evolution of the EAGLE intrinsic u-r CMD (with central and satellite galaxies coloured red and blue respectively) see http://community.dur.ac.uk/j.w.trayford/media/CMD_evolution_EAGLE.mp4.