Effect of correcting the photometry of sources for which the IPD used a default colour. Top panel: a colour-colour diagram of the reddest main sequence stars in the local neighbourhood with parallax greater than 3 mas. The points are colour coded using the ν_eff value used inthe processing. If the default ν_eff was used, then the points are coloured grey. Bottom panel: same sources but with corrected G-band photometry.