Not the northern lights

The sticky-backed plastic on window of the utility room (the kind you put on bathroom windows which are overlooked, if they are not already obscure glass) has a hologram effect, and when the sun shines through (which admittedly hasn't happened very often in the 3 months we've lived here) it projects rainbows onto the walls of the kitchen and living room. It puts me in mind of the Aurora Borealis. Happy Christmas/Jule, everyone.