I think that staying still and minimizing your scent as best you can are far more important than wearing camo or not. I don't think that orange is a disadvantage when deer hunting in ON but I know this is a big country and terrain varies a lot. Plus there are just too many wingnuts out here during gun season for it to be safe to not wear orange.
I will never forget something that happened 2 years ago to me and a buddy. We were walking during deer season in ON, on a trail on private property, where we had exclusive rights to hunt, on our way to our respective posts. This was shortly after sunrise, but there was plenty of light. I hear a whistle and I knew it was a person. I also knew by the sound it was coming from very close by. So I say to my buddy "you hear that? there is someone RIGHT here", he says no, nobody here. Then there is another whistle, this time louder. We were straining to make the person out. There was no cover nearby, no leaves, bush or anything. Mature stand of trees. So then we see the guy wave his arm from maybe 30 yards away. I was almost looking right at him! Ever seen the movie predator? It was like that! Spooky. Guy was out there with his deer rifle, during the season, no orange. Told us he knew he was on private property, knew it was signed, but he wasn't hunting! Just "passing through"!!! I know camo doesn't always work that well, but it can. Guy gave us crap for wearing orange! Said, you guys are never getting anything dressed like that. Our predator eyes are better than most will give credit for too. So point is, if it can work that well to fool a person's eyes, then it must work really well for game. Sorry for straying off topic a little, don't mean to derail the discussion.