Embellish outside of blue pack (6)
I believe the answer is:
bedeck
'embellish' is the definition.
(bedecking is a kind of embellishing)
'outside of blue pack' is the wordplay.
'outside of' means to remove the middle letters.
'pack' becomes 'deck' (deck is a kind of pack**).
'blue' with its centre removed is 'be'.
'be'+'deck'='BEDECK'
(Other definitions for bedeck that I've seen before include "Adorn, embellish" , "Trim" , "Lavishly decorate" , "Adorn, cover with decorations" , "Festoon; decorate" .)