Do what's colourful but unoriginal (5)

I believe the answer is:

redye

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'do' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'colourful but unoriginal' is the wordplay.
'colourful' becomes 'red' (similar in meaning).
'but unoriginal' becomes 'ye' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'red'+'ye'='REDYE'

'what's' acts as a link.

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I've seen this clue in the Evening Standard.

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