Blue robe stripped off ahead of public disturbance (7)
I believe the answer is:
obscene
'blue' is the definition.
(blue can mean pornographic)
'robe stripped off ahead of public disturbance' is the wordplay.
'stripped off' says to take the centre (the outer letters are stripped off).
'ahead of' means one lot of letters go next to another (some letters go in front of others).
'public disturbance' becomes 'scene' (I've seen this in another clue).
The middle of 'robe' is 'ob'.
'ob'+'scene'='OBSCENE'
(Other definitions for obscene that I've seen before include "Lewd or loathsome" , "Rude" , "Prurient" , "Highly offensive" , "Salacious" .)