Taught tout to change colour (7)
I believe the answer is:
tutored
'taught' is the definition.
(synonyms)
'tout to change colour' is the wordplay.
'to change' indicates anagramming the letters.
'colour' becomes 'red' (red is a kind of colour).
'tout' is an anagram of 'tuto'.
'tuto'+'red'='TUTORED'
(Other definitions for tutored that I've seen before include "Taught small groups" , "Rude tot (anag.)" , "Gave private lessons to" , "Coached" , "Instructed" .)