Translate 'blue tits' for foreign film caption (8)
I believe the answer is:
subtitle
'foreign film caption' is the definition.
(I've seen this before)
'translate blue tits' is the wordplay.
'translate' indicates an anagram (I've seen this in other clues).
'blue'+'tits'='bluetits'
'bluetits' anagrammed gives 'SUBTITLE'.
'for' is the link.
(Other definitions for subtitle that I've seen before include "Translation of foreign dialogue, in a film say" , "Translation of dialogue superimposed on film" , "Provide wording for TV" , "small print?" , "Screen caption" .)