Colour in small gardens (4)
I believe the answer is:
skew
'colour' is the definition.
(both can mean to bias or distort)
'small gardens' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'gardens' becomes 'Kew' (Kew Gardens in London).
's'+'kew'='SKEW'
'in' acts as a link.
(Other definitions for skew that I've seen before include "Colour" , "Turn or twist around" , "Place(d) obliquely" , "Not symmetrical" , "Oblique, make crooked" .)