敵の援軍が到着し、味方の旗色が一気に悪くなった。
Enemy reinforcements arrived, and the tide of battle quickly turned against our side.
議論が進むにつれて、反対派の旗色が悪くなってきた。
As the debate went on, things started going badly for the opposition.
彼は旗色をうかがってから、どちらにつくかを決めるつもりだ。
He intends to see which way the wind is blowing before deciding which side to take.