Hour in deep sleep showing quality of shade (6)
I believe the answer is:
chroma
'quality of shade' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
I also know that both 'quality' and 'shade' relate to this answer.
'hour in deep sleep' is the wordplay.
'hour' becomes 'hr' (synonyms).
'in' means one lot of letters goes inside another.
'deep sleep' becomes 'coma' (I've seen this before).
'hr' going within 'coma' is 'CHROMA'.
'showing' is the link.
Can you help me to learn more?
(Another definition for chroma that I've seen is " hue".)