The most common and most likely answer to this crossword clue is the 6 letter word CHALKY
I've seen this crossword clue in The Times
C
H
A
L
K
Y
More clues leading to the result CHALKY
Buddy explains!

The straight part
We know that "Ashen" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case ashen = chalky.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CHALKY mean?
CHALKY adjective- Consisting of or containing chalk.
- Resembling chalk in some way.
- Of a tournament: in which the favorites win, or expected to win, most of the games.