Healthy colour in Istanbul (3)
I believe the answer is:
'healthy colour' is the definition.
'in istanbul' is the wordplay.
'in' indicates a hidden word.
'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" .)