Colourings? Yes, time to be put into puddings (9)

I believe the answer is:
dyestuffs
'colourings?' is the definition.
Although both the answer and definition are plural nouns, I cannot see how one could define the other.
'yes time to be put into puddings' is the wordplay.
'time' becomes 't' (abbreviation).
'to be put into' indicates putting letters inside.
'puddings' becomes 'duffs' (duff is a kind of pudding).
'yes'+'t'='yest'
'yest' put within 'duffs' is 'DYESTUFFS'.
Can you help me to learn more?
(Other definitions for dyestuffs that I've seen before include "Colourants" , "Colouring substances" .)
