Spectrum of 67P/C-G obtained in July 2007. The spectrum is normalised to unity at 6380 Å. In the original spectrum (grey line) the binned spectrum (black line) and the spectral reflectivities obtained from the photometric colour indices of the nucleus (diamonds) are superimposed. Signal-to-noise ratio (S/N) and corresponding relative error (σ) in the binned spectrum are reported with the wavelength range (λ) used for their determination.