The part where Katniss meets the District 11 Tribute, and she says:
“The woman, Seeder, looks almost like she could be from the Seam, with her olive skin and straight black hair streaked with silver. Only her golden brown eyes mark her as from another district.”
And we already know what the people in District 11 are.
*I know it’s just speculation and nothing has been confirmed, I’m just offering my opinion, speaking as if he had been cast*
He is not what I had in mind for Finnick. I trust Lionsgate and Suzanne to make a good choice, so if they were happy with him then I guess he’d be good for the role. Although I didn’t imagine Finnick as black. I wouldn’t have a problem with it but in fairness it wouldn’t be very true to the book, in which Finnick is clearly described as having ”tan skin & bronzed-colored hair”. I know it’s a very broad description, but it is highly unlikely for a dark skinned person to be born with bronze hair (which is in my mind golden blonde but it may be closer to red/ginger). If Finnick was supposed to be black then he’d be written to support this, I think.
He has the nice green eyes though. Personally I picture Finnick more like Garrett Hedlund, but I don’t have a specific actor in mind.