Galaxy bias parameters b(ℓ) and r(ℓ) in the Millennium Simulation data set as a function of angular scale ℓ (x-axis) and galaxy redshift (curves; see key for mean redshifts). The top numbers denote the corresponding aperture radius (arcmin) of the aperture statistics that were utilised to infer the galaxy bias from angular correlation functions (polynomial filter). The left panels correspond to red galaxies with m_r < 25 and m_u − m_r > 2.2 and the right panels to blue galaxies with m_r < 25 and m_u − m_r ≤ 2.2. The error bars denote the remaining standard error based on 128 simulated survey fields with one square degree each.