Comparison of composite spectra from the full VLT five year sample split in color, without color correction (top panel), with color correction using the SALT2 color law (middle panel) and with color correction using the CCM law (bottom panel). In each panel, the blue spectrum is built from c < 0 SNe Ia, the red spectrum from c ≥ 0 SNe Ia. No recalibration has been applied to individual spectra (see text for details). Residual host-galaxy lines have been removed. A ± 1σ range is plotted.