What does the cryptic crossword clue "Ashen, but work thus to get some colour (8)" mean?

The definition is "Ashen,". The wordplay uses an anagram. anagram of ASHEN BUT = SUNBATHE; definition: "Ashen," The answer is SUNBATHE.

Ashen, but work thus to get some colour (8)

Guardian Cryptic #29495 | 6 Down | 2024-09-23 flower