I wouldn't look at it this way, from what I read in interwiews GRRM is trying to move away from that narrative of ridged defined "good" and "bad" guys. I'm pretty sure as the story concludes we're going to get some conclusions and characters who sea saw between being "good" and "bad". I would def hold up before coming to that conclusion.
He already has done that. He's great at it. Jaime Lannister is a good example. He fukks his sister, tosses kids out windows, but as we've seen in the last 2 season he does have a sense of honor and feels bad about how people perceive him as the Kingslayer.
However, I don't know how anybody can watch the show and not classify the Lannisters as villains. Not all of them, but for the most part. They took the throne under false pretenses, they're incestuous, and the last person they put on the throne was a murderous sociopath. The Red Wedding alone solidifies them as villains, they couldn't even take credit for that it was so dishonorable.
They're just 3 dimensional villains.
Fred.