Optical/UV light curves of J0458−5202 for observations Sw3–8, in which Swift UVOT observed with all six filters. For this overplot, the V, B, W1, M2, and W2-band light curves have been offset by the magnitude values indicated in the top left corner such that their mean magnitudes across all six observations match the mean of the U-band light curve. This action helps to illustrate the optical/UV spectral variability as a function of flux; as demonstrated in Sect. 4, such spectral variability is consistent with bluer-when-brighter behavior, and not a product of variable extinction.