Duo note more than one colour (3-4)
I believe the answer is:
two-tone
'one colour' is the definition.
The definition suggests an adjective which matches the answer.
'duo note more' is the wordplay.
'duo' becomes 'two' (a duo is two people).
'note' becomes 'tone' (synonyms).
'more' says to put letters next to each other (some letters added to the previous ones).
'two'+'tone'='TWO-TONE'
'than' acts as a link.
Can you help me to learn more?
(Other definitions for two-tone that I've seen before include "Having mixed colours" , "With a pair of colours" .)