Mum clothes a nice man in purple (7)
I believe the answer is:
Here is my best explanation:
'purple' is the definition.
'mum clothes a nice man' is the wordplay.
'mum' becomes 'ma' ('ma' can be a synonym of 'mum').
'clothes' is an insertion indicator.
'nice man' becomes 'gent'.
'ma' going around 'agent' is 'MAGENTA'.
'in' is the link.