Strangely coloured flathead, or?

[nadders]

Hey guys,

twice this week i've seen the same fish cruising around the very shallow water over a rock ledge at bretts wharf (standing at the walkway down to the pontoon and looking toward the city, just under there). Its shaped like a decent sized flatty, maybe 50cm long, but its jet black and has a bright white tail. at first i thought bar-tailed flathead but its a solid white tail and a solid black body. reckon its just a miscolouration or what?

cheers