Swansea has lost colour (3)
I believe the answer is:
wan
'lost colour' is the definition.
'wan' can be an answer for 'colour' (I have seen 'Lacking colour ' mean 'wan' so perhaps 'colour' could also mean 'wan'). I'm not sure about the 'lost' bit.
'swansea has' is the wordplay.
'has' says the answer is hidden in the clue.
'WAN' is hidden in the letters of 'swansea'.
Can you help me to learn more?
(Other definitions for wan that I've seen before include "Pale and pinched-looking" , "Pale, looking exhausted" , "Pale and weak-looking" , "Blanched" , "Pallid" .)