SED evolution of AT 2019abn, AT 2019ahd, NGC 300 OT, and AT 2019udc. Flux measurements are shown as black circles. In the first phases of their evolution, a single blackbody closely approximates the evolution of the SED. At later phases a second cooler blackbody is needed to reproduce the NIR flux excess. Epochs are reported with respect to maximum light. Flux shifts have been applied for clarity.