Range of colours allowed having spread around (7)
I believe the answer is:
palette
'range of colours' is the definition.
(I've seen this before)
'allowed having spread around' is the wordplay.
'allowed' becomes 'let' (to let is to allow or permit).
'having spread' becomes 'pate' (I can't explain this - if you can you should believe this answer much more).
'around' indicates putting letters inside.
'let' going inside 'pate' is 'PALETTE'.
Can you help me to learn more?
(Other definitions for palette that I've seen before include "Artist's board with thumb-hole" , "Board for an artist" , "Variety of tones" , "Artist's paint mixing board" , "selection of colours" .)