The V − K colours of the variable stars found in the period range 7500 s to 10 000 s. The candidate W UMa stars from Table 1 are shown as filled, larger symbols at half their proposed orbital period in each case. All are redder than the average colours of the rest of the sample. The structures seen amongst the other points are due to systematic noise giving rise to false periods close to 1/9, 1/10 and 1/11 of a sidereal day, with weaker structures at 1/9, 1/10 and 1/11 of a solar day.