Comparison of input (x axis) and output (y axis) Sérsic index values, n_B, for galaxies at m_r,B+D,Sim < 19.5 mag from multi-band fits (top) and single-band fits (bottom). Darker colours are used to indicate brighter objects, with 16 < m_r,B+D,Sim < 19.5 mag. Blue lines indicate median and 16/84 percentiles, and the green line represents a one-to-one line that indicates perfect fits.