Think, as you do, red is coming back (8)
I believe the answer is:
consider
'think' is the definition.
(I know that think can be written as consider)
'do red is coming back' is the wordplay.
'do' becomes 'con' (both can mean to defraud).
'coming back' shows that the letters should be reversed in order.
'red'+'is'='redis'
'redis' back-to-front is 'sider'.
'con'+'sider'='CONSIDER'
'as you' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for consider that I've seen before include "Reckon, deem" , "Muse, mull over" , "Go over something in one's mind" , "Contemplate" , "Deliberate" .)