Residual amplitudes A_res, d(ν) obtained for the reference models Commander (top) and GNILC (bottom). Red and blue colors represent the EE and BB results, respectively. These values are estimated by averaging between ℓ-range 4–32 and normalizing to the amplitudes of the residuals obtained from the Planck data A_res(ν). See Eq. (12) for details. Results for f_sky = [80, 90, 97]% are shown from left to right. The absolute value of BB negative results found at 100 GHz for f_sky = 80% is shown in gray.