Small bill, pinkish (5)
I believe the answer is:
lilac
'pinkish' is the definition.
Both the answer and definition are adjectives. Perhaps you can see a link between them that I don't see?
'small bill' is the wordplay.
'small' becomes 'lil' (I can't justify this - if you can you should believe this answer much more).
'bill' becomes 'ac' (short for account).
'lil'+'ac'='LILAC'
Can you help me to learn more?
(Other definitions for lilac that I've seen before include "Shrub with fragment purple or white flowers" , "Light purple - shrub" , "Tree - pinkish-purple colour" , "Pale mauve colour for a flower" , "I call (anag)" .)