Some swear thyme is blue (6)

I believe the answer is:

earthy

'blue' is the definition.
(both can mean sexual)

'some swear thyme is' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'EARTHY' can be found hidden inside 'swear thyme is'.

(Other definitions for earthy that I've seen before include "Coarse or gross" , "Gross, unrefined" , "Coarse; unsophisticated" , "Coarse like clay" , "Of the soil, lusty" .)

I've seen this clue in The Times.

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