In case it's the wrong shade for the exterior (8)
I believe the answer is:
sheathed
'in case' is the definition.
(I've seen this before)
'it's the wrong shade for the exterior' is the wordplay.
'it's' becomes 'he' (I can't justify this - if you can you should give a lot more credence to this answer).
'the wrong' indicates an anagram.
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'exterior' is an insertion indicator.
'shade' after 't' is 'tshade'.
'tshade' with letters rearranged gives 'sheatd'.
'he' inserted within 'sheatd' is 'SHEATHED'.
Can you help me to learn more?
(Other definitions for sheathed that I've seen before include "Put sword back in covering" , "put in protective cover" , "Covered for protection" , "Encased in close-fitting covering - say sword" , "in a case like this" .)