The variation of B − V with decreasing V magnitude of the current obscuration, with the τ = 40 model overplotted. The size of the plotted circle increases with time. Note that the first points are not evenly spaced in time for the current obscuration. At minimum V magnitude there are many colour variations of up to B − V = 0.5 which is an intrinsic property of R CrB stars. The photometric data are from the AAVSO.