Statement of principles: firm is in the red (actually, the opposite) (5)
I believe the answer is:
credo
'statement of principles' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for credo that I've seen before include "ideology" , "Dogma" , "Formal statement of beliefs" , "Formal statement of principles" , "Faith - I believe" .)