Secretive person in the pink (6)
I believe the answer is:
oyster
I believe this is a double definition.
'secretive person' is the first definition.
(I've seen this before)
'pink' is the second definition.
(oyster pink is a shade of pink)
'in the' acts as a link.
(Other definitions for oyster that I've seen before include "Edible shellfish" , "It produces pearls" , "Capital card" , "offers all one could desire" , "Native -- seafood" .)