Purple colour (5)
I believe the answer is:
lilac
'purple colour' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for lilac that I've seen before include "Tree - pinkish-purple colour" , "Shade" , "Pale mauve colour for a flower" , "Purplish in colour" , "Pinkish purple - shrub" .)