Being extravagant with jewellery all over uniform (6)

I believe the answer is:

bluing

'being extravagant' is the definition.
(blue can mean to spend extravagantly)

'jewellery all over uniform' is the wordplay.
'jewellery' becomes 'bling' (informal term for jewellery).
'all over' means one lot of letters goes inside another.
'uniform' becomes 'U' (phonetic alphabet: alpha, bravo, charlie etc.).
'bling' placed around 'u' is 'BLUING'.

'with' is the link.

I've seen this clue in The Guardian.

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