Grey Marlin in dreams
A large, fighting ocean fish — strength that takes the longest line to land.
How grey changes the reading
Grey colour layers ambiguity onto the symbol. The base meaning is still there, but the dream is saying you do not yet have the colour information — the situation has not declared itself.
The base reading of Marlin
A marlin in a dream is the dream's image of a goal that, once you hook it, will fight for hours. Marlins are not given up easily; the contest is famously long and physical. The dream brings the fish when an ambition you have been chasing has finally taken the bait, and the next phase is endurance, not pursuit. A marlin still on the line is the dream telling you the work is real and worth the strain. A marlin breaking off is the dream marking that you spent the first energy on the chase and did not save enough for the fight.