Flag of many colours (4)
I believe the answer is:
iris
'flag' is the definition.
(type of iris flower)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for iris that I've seen before include "One controlling pupil' s reactions" , "bloomer?" , "pupil's governor" , "Woman" , "Flag or flower in the eye" .)