Predicted reddening variation along the DG Tau B redshifted lobe for the conical CO outflow and envelope. The red points are the extinction values estimated from the H₂ ro-vibrational transitions in Sect. 4.3. The black curve shows the expected extinction at 2.12μm as a function of distance from the source due to the CO conical redshifted outflow using the mass flux estimated in DV20. The black dashed curve represents the extrapolation of the model below 300 au assuming a constant CO mass flux. The blue line corresponds to the extinction profile for a spherical envelope in free fall with an infall rate of 4.5 × 10⁻⁶ M_⊙ yr⁻¹.