The most common and most likely answer to this crossword clue is the 3 plus 5 letter word PEA GREEN
I've seen this crossword clue in The Daily Telegraph
P
E
A
G
R
E
E
N
More clues leading to the result PEA GREEN
Buddy explains!
The straight part
We know that "Shade" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shade = pea green.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.