I have a potted oleander that spends summer outside and winter inside. It discolours similarly some years during fall when I leave it out as long as possible, even through frosts, until it gets so consisently cold I have to bring it into the basement. The winters are so long here that once it's indoors it won't get outside again until probably May, hence I delay its coming in as long as possible - it can take some cold but does protest at too much.
