The pier is black, it would seem (5)
I believe the answer is:
jetty
'the pier' is the definition.
(I've seen this in another clue)
'black it would seem' is the wordplay.
'black' becomes 'jet' (similar in meaning).
'it would seem' becomes 'ty' (I can't explain this - if you can you should believe this answer much more).
'jet'+'ty'='JETTY'
'is' is the link.
Can you help me to learn more?
(Other definitions for jetty that I've seen before include "Wharf" , "Small landing stage" , "Quay" , "Pier - landing stage" , "Dock" .)