Warm colour with similar qualities (7)
I believe the answer is:
kindred
'with similar qualities' is the definition.
(as in kindred spirits)
'warm colour' is the wordplay.
'warm' becomes 'kind' (synonyms).
'colour' becomes 'red' (red is a kind of colour).
'kind'+'red'='KINDRED'
(Other definitions for kindred that I've seen before include "Family - like" , "Affinity" , "Associated - relations" , "Relatively" , "Family - similar" .)