Filming hosts prepare food dye (7)
I believe the answer is:
carmine
'food dye' is the definition.
(carmine is a type of food dye)
'filming hosts prepare' is the wordplay.
'filming' becomes 'cine' ('cinema' in French).
'hosts' is an insertion indicator (inserted letters are welcomed or hosted).
'prepare' becomes 'arm'.
'cine' enclosing 'arm' is 'CARMINE'.
(Other definitions for carmine that I've seen before include "Bright red" , "Vivid red colour" , "Crimson pigment" .)