Monks maybe yellow, turning another colour (5)
I believe the answer is:
order
'monks' is the definition.
'yellow turning another colour' is the wordplay.
'yellow' becomes 'or' (heraldic term).
'turning' is a reversal indicator.
'another colour' becomes 'red' (red is a kind of colour. I am not sure about the 'another' bit.).
'red' backwards is 'der'.
'or'+'der'='ORDER'
'maybe' acts as a link.
Can you help me to learn more?
(Other definitions for order that I've seen before include "booking" , "Symmetry" , "See 20" , "the Speaker often calls for" , "Select from menu" .)