Colourful range of crumpets (8)
I believe the answer is:
spectrum
'colourful range' is the definition.
'spectrum' can be an answer for 'range' (a spectrum is a range or variety). I'm not certain of the 'colourful' bit.
'of crumpets' is the wordplay.
'of' indicates anagramming the letters (the answer comes from or 'of' the letters).
'crumpets' with letters rearranged gives 'SPECTRUM'.
Can you help me to learn more?
(Other definitions for spectrum that I've seen before include "Range of colour produced by a prism" , "The bands of colur as seen in rainbow" , "Bands of colour in crumpets" , "Crumpets (anag)" , "Full range of colour" .)