Two-colour plots of V − J vs. J − H for all systems in our sample with 2MASS/UKIDSS colours, V magnitudes and low reddening (E(B − V) < 0.1; light grey circles: WD companion, grey circles: dM companion, dark grey circles: unknown companion type). Most of the systems show no excess from a companion. The systems showing an infrared excess which indicates a cool companion are named. For comparison, 4 sdB binaries with confirmed G/K-type companions (light grey triangles) are shown (Vos et al. 2012, 2013). All colours were corrected for reddening.