Profound eddy swirled when so coloured (4-4)

I believe the answer is:

deep-dyed

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'so coloured' is the definition.
The definition and answer can be both related to change as well as being past participle verbs.
Perhaps you can see a link between them that I can't see?

'profound eddy swirled' is the wordplay.
'profound' becomes 'deep' (synonyms).
'swirled' indicates an anagram.
'eddy' is an anagram of 'dyed'.
'deep'+'dyed'='DEEP-DYED'

'when' acts as a link.

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I've seen this clue in the Sydney Morning Herald.

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