B versus V flux variations of 3C 120 in the aperture. Each measurement is drawn as a thin cross in which the line length corresponds to the photometric uncertainties in the respective filters. The yellow filled area is the assumed host color Γ_BV,Host, drawn to cover B = (1.70 ± 0.27) mJy and V = (4.01 ± 0.62) mJy host fluxes, as determined by Sakata et al. (2010) in an aperture. Our host flux estimate is the datapoint in the red circle. All data from 2009 until 2015 was used to determine the AGN slope. The black continuous line covers the upper and lower standard deviations in the AGN slope, given by the OLS bisector fit.