Are in the red when brought up (6)
I believe the answer is:
reared
'brought up' is the definition.
(rearing is a kind of bringing up)
'are in the red' is the wordplay.
'in the' is an insertion indicator.
'are' put inside 'red' is 'REARED'.
'when' acts as a link.
(Other definitions for reared that I've seen before include "Raised" , "Nurtured - rose on hind legs" , "Fostered, brought up" , "Provided and cared for during childhood" , "upright" .)