Night-club looked grim, having changed hue (11)
I believe the answer is:
discoloured
'changed hue' is the definition.
'discoloured' can be an answer for 'changed' (discolouring is a kind of changing). I am not sure about the 'hue' bit.
'night-club looked grim' is the wordplay.
I cannot quite see how this works, but
'club' could be 'disco' (night club) and 'disco' is found in the answer.
The remaining letters 'loured' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'having' acts as a link.
Can you help me to learn more?
(Other definitions for discoloured that I've seen before include "with poor tone?" , "Stained; faded" .)