Intended recipient of notice sees red, being replaced (9)
I believe the answer is:
addressee
'intended recipient' is the definition.
(I've seen this before)
'notice sees red being replaced' is the wordplay.
'notice' becomes 'ad'.
'being replaced' indicates an anagram.
'sees'+'red'='seesred'
'seesred' anagrammed gives 'dressee'.
'ad'+'dressee'='ADDRESSEE'
'of' acts as a link.
(Other definitions for addressee that I've seen before include "One sent letter" , "The person to whom letter is delivered" , "The one to whom the message is sent" , "Person named on an envelope" , "He's written to" .)