Healthy colour in Istanbul (3)
I believe the answer is:
tan
'healthy colour' is the definition.
'in istanbul' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TAN' is hidden within 'istanbul'.
(Other definitions for tan that I've seen before include "Brown colour acquired from sun" , "Yellowish-brown colour" , "function" , "Make black and blue" , "Acquire a sunburn" .)