Colourful result of hitting buffers? (7)

I believe the answer is:

shiners

I believe this clue is a double definition.

'colourful result of hitting' is the first definition.
(shiner can mean a black eye)

'buffers?' is the second definition.
(people who buff or shine things)

(Other definitions for shiners that I've seen before include "Black eyes (sl.)" , "Fish with colourful markings" .)

I've seen this clue in The Guardian.

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