Colour-mass-density diagram coloured by environment and colour of galaxies. Red points represent regions belonging to the red galaxies in the field. Orange is used for the regions of the red galaxies in groups, blue points are for the regions of blue galaxies in the field, and cyan points are for regions of blue galaxies in groups. Stars represent the median value for each galaxy type in each mass-density bin. Squares represent the same as in Fig. 2.