This came up in a game yesterday, when there's a door on a map, it looks like part of it the small tip of the door is purple which I think indicates its a wall, but to have LOS to a door for override, do you have to have LOS to the silver part of the door? or the tip of the wall where the door branches from?

I am pretty sure it is any part of the door.

You always count terrain lines to the corners of the 1" grid, unless it's a specifically drawn 'beveled' corner (like in the tractor beam area on Death Star).

I'm assuming, Xanthan, that yo're talking about the main doors on the Cloud City map? On that map, the artwork makes it look like the door doesn't actually span the 2" opening. However, it is treated as though it goes all the way to that corner. So, as long as you can draw legal LOS to anywhere along that 2" line, then you can use Override on it, even if the artwork lines overlap a little funny.

If that doesn't answer your question, perhaps a quick screenshot with Vassal would help us understand your question.

Actually I was referring to the Rancor Pit map, but yeah some of the artwork on Rancor pit map was overlapping so that does answer my question. Thanks for the answers.