Band of colour (8)
'band of colour' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for stripe that I've seen before include "Band of contrasting colour" , "Line of different colour - indicator of rank" , "Streak" , "Priest (anag)" , "Braid showing military rank" .)
(Other definitions for spectrum that I've seen before include "'Broad range, scope (8)'" , "Complete colour range" , "Broad range of related items" , "A broad range, of colours say" , "An entire range of related qualities of crumpets" .)