Comparison of the color–color diagrams of the Chandra observation ObsID 3814 using the MEG M1 arm with different models. Left: empirical polynomial fit. Middle: neutral grid using the tbabs absorption model for different covering fractions and the same continuum photon index Γ = 1.6. Right: homogeneously ionized absorber using the warmabs model with continuum photon index Γ = 1.6 and a covering fraction of 0.95. The equivalent absorbing column density,N_H, changes from 0.25 × 10⁻²² cm⁻² to 32 × 10⁻²² cm⁻² along each line, with each line showing the track for a different ionization parameter log ξ as indicated by the different colors.