Power spectrum of residual foreground contamination (left panel) and noise (right panel) with NILC (solid lines) and cMILC (dashed lines) on f_sky = 50% of the sky for the M0 (blue) and M5 (orange) configurations. For reference, we show the input CMB B-mode signal (r = 0, black dash-dotted line), the primordial B-mode signal expected from theory for values ranging from r = 10⁻² down to r = 10⁻³ (gray-shaded area), and the residual lensing cosmic variance (yellow-shaded area) for no delensing (A_L = 1) up to 90% delensing (A_L = 0.1). All the spectra are binned with a multipole bin size of Δℓ = 16.