Left panel: difference of the two upper images is shown in the bottom panel. The two upper images are simulated by only changing the fiducial parameter of the elliptical population to the perturbed parameter values by +Δθ₁ (top) and −Δθ₁ (middle). Only yellow or red elliptical galaxies remain, which confirms that affects the density of ellipticals in the simulations. Right panel: difference of the two upper images is shown in the bottom panel. The two upper images are simulated by only changing the fiducial parameter of the spiral population to the perturbed parameter values by +Δθ₂ (top) and −Δθ₂ (middle). Only blue spiral galaxies remain, which confirms that affects the density of spirals in the simulations. These RGB color images are obtained from the i′, r′, g′ filters.