The most common and most likely answer to this crossword clue is the 8 letter word YELLOWED
I've seen this crossword clue in Independent
Y
E
L
L
O
W
E
D
Buddy explains!

The straight part
We know that "turned pale" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case turned pale = yellowed.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 YELLOWED mean?
YELLOWED verb- To become yellow or more yellow.
- To make (something) yellow or more yellow.
- Having a yellow color (or discoloration), especially when due to age; having been made yellow.