Copper-coloured light? (4,4)

I believe the answer is:

blue lamp

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'copper-coloured light?' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'coloured light?' is the wordplay.
'coloured' becomes 'blue' (similar in meaning).
'light?' becomes 'lamp' (lamp is a kind of light).
'blue'+'lamp'='BLUE LAMP'

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I've seen this clue in the Evening Standard.

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