What monarch wears brown in the capital? (7)
I believe the answer is:
teheran
'the capital?' is the definition.
(Teheran is an example)
'what monarch wears brown' is the wordplay.
'what' becomes 'eh' (sound used to ask 'what?' or 'pardon?').
'monarch' becomes 'ER' (abbreviation for Elizabeth Regina, British Queen).
'wears' means one lot of letters goes inside another.
'brown' becomes 'tan' (tan is a kind of brown).
'eh'+'er'='eher'
'eher' put into 'tan' is 'TEHERAN'.
'in' acts as a link.
(Other definitions for teheran that I've seen before include "Near the (anag) - capital" , "Iran capital (one spelling)" , "Iran's capital" , "City" .)