Haven't seen an amberjack in years, but the name amberjack is a giveaway from my memory. They had a distinct golden/grey coloration, but did have a drak top,lighter bottom.
They are notorious for deep down slugfests as opposed to surface action, and like all jacks, do that death spiral thing; about 20' down beneath your boat where they go around and around and around in a tight circle; yielding each inch of vertical depth oh so relunctantly.