Bright pink apron mum Penny possesses (6)
I believe the answer is:
shrimp
'bright pink' is the definition.
(shade of pink)
'apron mum penny possesses' is the wordplay.
'apron' becomes 'rim' (both can mean something's edge).
'mum' becomes 'sh' (both are used to tell someone to be quiet).
'penny' becomes 'p' (short for pence).
'possesses' is an insertion indicator.
'sh'+'p'='shp'
'rim' inserted within 'shp' is 'SHRIMP'.
(Other definitions for shrimp that I've seen before include "Seafood" , "Diminutive person" , "Small edible shellfish, pink when boiled" , "ingredient of cocktail" , "no giant" .)