Magnitude error as a function of galaxy colour is shown for aperture photometry done using 2, 14, and 100 pixel apertures in the lower left, upper left, and lower right panels, respectively. The mag errors as a function of colour for isophotal photometry is shown in the upper right panel. The 14 pixels aperture and isophotal photometry have higher colour accuracy than the 2 and 100 pixels aperture photometry, which explains the photo-z results.