《太平广记·卷四百零九·草木四》
当时正是初冬。那棵牡丹本来开紫色花。等到花开时一看，变成黄的红的了，每一朵都有一联诗，字迹分明，是紫色的。
时冬初也，牡丹本紫，及花发，色黄红历缘。
It was early winter at the time. The peony was originally purple. When it bloomed, it turned yellow and red, each flower had a couplet of poem, the handwriting was clear, and it was purple.