Film dog in colour, one interrupting service (3,3,3)
I believe the answer is:
rin tin tin
Here is my best explanation:
'film dog' is the definition.
(famous Hollywood dog)
'in colour one interrupting service' is the subsidiary indication.
'colour' becomes 'tint' (tint is a kind of colour**).
'one' becomes 'i' (Roman numeral).
'interrupting' indicates putting letters inside.
'service' becomes 'rn' (abbreviation for Royal Navy).
'intinti' inserted inside 'rn' is 'rintintin'.
(Other definitions for rin tin tin that I've seen before include "shot dog", "Canine star of many films", "Fabled canine" and "Dog Star".)