A shade of grievance (7)
I believe the answer is:
umbrage
This clue might be a double definition.
'a shade' is the first definition.
(thesaurus)
'grievance' is the second definition.
The definition and answer can be both feelings as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'of' acts as a link.
Can you help me to learn more?
(Other definitions for umbrage that I've seen before include "Resentment, offence" , "The sulks" , "Take this to feel offence" , "It''s given or taken in offence" , "Displeasure" .)