Sentence

青菜に塩。

青菜(あおな)(しお)
Be utterly dejected.
Sentence

彼、今日、精彩がないね。青菜に塩だね。

(かれ)今日(きょう)精彩(せいさい)がないね。青菜(あおな)(しお)だね。
He seems really depressed and lifeless today. I wonder what took the wind out of his sails.