The most common and most likely answer to this crossword clue is the 5 letter word LOVAT
I've seen this crossword clue in The Guardian
L
O
V
A
T
More clues leading to the result LOVAT
Buddy explains!

The straight part
We know that "a sort of green" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a sort of green = lovat.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 LOVAT mean?
LOVAT noun- A dusty blue-green colour.
- Of a dusty blue-green colour.