Piece of corn with a light coating of blue pigment (6)
I believe the answer is:
cobalt
'blue pigment' is the definition.
(I've seen this before)
'piece of corn with a light coating' is the wordplay.
I cannot quite see how this works, but
'piece' could be 'b' (abbreviation for bishop) and 'b' is located in the answer.
'of' could be 'o' and 'o' is located in the answer.
'a' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'of' acts as a link.
Can you help me to learn more?
(Other definitions for cobalt that I've seen before include "Bright blue pigment" , "Magnetic metal" , "Deep blue colour" , "Metal element" , "kind of blue" .)