Stream reflecting no light, it's very dark (3-5)
I believe the answer is:
jet black
'very dark' is the definition.
(I've seen this in another clue)
'stream reflecting no light' is the wordplay.
'stream' becomes 'jet'.
'reflecting no light' becomes 'black' (I can't explain this - if you can you should give a lot more credence to this answer).
'jet'+'black'='JET-BLACK'
'it's' is the link.
Can you help me to learn more?
(Other definitions for jet black that I've seen before include "Glossy and very dark" , "very dark prospect" , "Very darkest colour" .)