Was in the red (4)
I believe the answer is:
owed
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">was in the red</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for owed that I've seen before include "Outstanding" , "(Sum) due for payment" , "In debt to" , "Was obliged to pay" , "Was due to pay" .)