Place is in perfect shade (6)
I believe the answer is:
purple
'shade' is the definition.
(I know that purple is a shade)
'place is in perfect' is the wordplay.
'place' becomes 'pl' (abbreviation used in postal addresses).
'is in' indicates putting letters inside.
'perfect' becomes 'pure' (synonyms).
'pl' put into 'pure' is 'PURPLE'.
(Other definitions for purple that I've seen before include "Colour associated with imperial authority" , "Colour of the angry" , "shade" , "Colour between 14dn and blue" , "Colour obtained from mixing red with blue" .)