Be in the red - in yellow even (3)
I believe the answer is:
owe
'be in the red' is the definition.
(I've seen this in another clue)
'in yellow even' is the wordplay.
'in' indicates a hidden word.
'OWE' can be found hidden inside 'yellow even'.
(Other definitions for owe that I've seen before include "Have outstanding" , "Are debtors" , "have favours to return" , "Be obliged to pay" , "Be in the red" .)