Relatively gentle colour? (7)
I believe the answer is:
kindred
'relatively' is the definition.
(I've seen this before)
'gentle colour?' is the wordplay.
'gentle' becomes 'kind' (I've seen this in another clue).
'colour?' becomes 'red' (red is a kind of colour).
'kind'+'red'='KINDRED'
(Other definitions for kindred that I've seen before include "[TRIBAL]" , "A ... spirit shares your feelings" , "Relatives" , "Related by blood - having similar qualities" , "Closely related" .)