花开富贵 is a modern set-phrase rather than a classical chengyu; it is not in
新华成语词典. It is paired almost exclusively with the peony (
牡丹), China's 'flower of wealth and rank,' and appears on New Year paintings, wedding decorations, and gift ceramics as a four-character blessing, usually alongside
富贵吉祥 or
万事如意.
