Differences between synthetic spectra (normalised flux) computed with only CN and TiO lines for five values of the effective temperature. The spectra were computed adopting [Fe/H] = [α/Fe] = 0.0 dex with R = 11 500 and 800 wlp for typical dwarf (log(g) = 4.5, V_micro = 1.0 km s⁻¹) and giant stars (log(g) = 1.5, V_micro = 2.0 km s⁻¹), top and bottom panels, respectively. Green and red background colours refer to dominant contributions of TiO and CN, respectively.