Colour gradients (g − i, g − r and u − g, from left to right) at z = 2, 1, 0 (from top to bottom) for the 10 galaxies (different colours) in the MNoW and WM models. Galaxies with major mergers since z = 2 are indicated by black-blue colours (those have typically the flattest colour gradients at z = 0), while galaxies with only minor mergers since z = 2 are illustrated by red-yellow colours (having steeper gradients). At r > 2Reff, present-day WM galaxies show negative colour gradients in the outer parts, which are steeper than for the MNoW galaxies.
(Hirschmann et al., 2015)