OJ287 is a blazar exhibiting high-amplitude variability in all the bands in which it has been studied, from x-ray to radio, over time scales ranging from minutes to decades. It has been particularly well studied in visible light, revealing no clear tendency to show bluer colours when brighter – an interesting anomaly compared to other blazars. It is also one of the active galactic nuclei in which it has proven most difficult to detect the host galaxy: either directly, by resolving it in images, or indirectly, by the change of colour at magnitudes sufficiently faint for the galaxy to be expected to make an important contribution to the total light from the system. Here, we investigate the colour variations of OJ287, finding a slow component of variation with an amplitude of ~0.2 magnitudes on a timescale of years, in both the B – V and V – R colour indices. We identify this tentatively with the effects of the major outbursts that occur every ~12 years. We also find that, contrary to previous findings, OJ287 does show a tendency to bluer colour when brighter, but that these trends are only visible in short segments of data covering a few months to a few years. We interpret this behaviour as due to multiple, overlapping components of emission coexisting, each with its own colour-magnitude correlation. Finally, we show that the colour changes OJ287 exhibits at faint magnitudes are consistent with the host being a giant elliptical galaxy with a magnitude of V = 18.0 and R = 17.1, and that this object can be detected unequivocally, if indirectly, with a backyard telescope.