Focus on the early evolution of the light curves and colours of AT 2023clx. Top panel: Early evolution of the light curves in the bluer bands for comparison with Fig. 2 in flux density space, normalised so that they are all equal to one at the first UVOT epoch. There is a clear wavelength dependence in the decline rate during the first ∼20 days post-peak: the bluer the band, the faster the decline. Bottom panel: Colour evolution of the light curves shown in the top panel with respect to the g-band. There appears to be a ‘rapid cooling’ (unusual for TDEs) that occurs during the first ∼20 days post-peak.