Color–color diagram of the 70 000 mock galaxies generated from M12 templates. The color indicates the redshift of the mock galaxy. The dotted line shows the color cut given by Amblard et al. (2010). Galaxies above this line are expected to have z ~ 2.6 and those under it are expected to have z ~ 1.8. The dashed line shows the selection of 500μm risers. The upper left region separated by this line selects galaxies with z> 4. The solid lines are our color cut method according to the distribution of the mock galaxies. The solid lines divided the diagram into four parts. From lower right to upper left these parts select galaxies at z< 0.5, 0.5 <z< 1.5, 1.5 <z< 2.5 and z> 2.5.