Greek king's unnatural russety hue (10)

I believe the answer is:

eurystheus

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'greek king's unnatural' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'russety hue' is the wordplay.
I cannot really see how this works, but
an anagram of 'hue' is 'heu' which is present in the answer.
an anagram of 'russety' is 'eurysts' which is within the left over letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

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I've seen this clue in The Times.

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