### Clue: Detain drunk, then vanish, say – a colourful treatment! (3-3-3)
### Answer: TIE-AND-DYE 
 ### Explanation: Definition: a colourful treatment
 **Anagram of**(drunk) DETAIN **plus**(then) **homophone of**(say) "die"(vanish;cease to exist).
Answer: Usually given as "tie-dye".