Coloured, turbulent eddy (4)
I believe the answer is:
dyed
'coloured' is the definition.
(dyeing is a kind of colouring)
'turbulent eddy' is the wordplay.
'turbulent' indicates an anagram.
'eddy' anagrammed gives 'DYED'.
(Other definitions for dyed that I've seen before include "Changed to a new colour" , "Stained - coloured" , "Cloth is often" , "Changed the colour of fabric" , "Artificially coloured" .)