Made a heap of money in a colourful case (5)
I believe the answer is:
piled
'made a heap' is the definition.
(I've seen this in another clue)
'money in a colourful case' is the wordplay.
'money' becomes 'l' (L can mean 'pounds').
'in' is an insertion indicator.
'a colourful case' becomes 'pied' (I can't justify this - if you can you should believe this answer much more).
'l' put inside 'pied' is 'PILED'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for piled that I've seen before include "Arranged in stacks" , "Heaped" , "put in a heap" .)