In their paper on delineating boundaries from geographic data, Reinbacher et al. [9] use a recolouring method to reclassify points so that the boundaries that separate points of different colours become more reasonable. They show that an iterative recolouring method converges after a finite, but exponential, number of steps. They also give, as an example, a triangulated point set with a specified re-colouring sequence that uses (n2 ) recolourings. In this note we revisit this recolouring problem and obtain a matching O(n2 ) upper bound.