Bob: I heard you started your own company. How is it going?
Fred: Terrible, actually. We are deep in the red.

In a budget, the positive numbers (showing profit) are black. The negative numbers (meaning you are losing money) are red. So when someone is in debt or losing money, we say they are “in the red”.

ボブ:会社を作ったってきいたけど、調子はどう?
フレッド;実は最悪。赤字ばっかり。

予算を書くとき、正の数(利益)は黒で、負の数(損失)は赤です。借金しすぎたり、お金を使いすぎたりする状態を「in the red」と言います。