No offence taken. In Scotland there are 2 main football teams, Rangers and Celtic and they hate each other. Rangers play in blue and Celtic play in green. It can be quite enforced on a young age what team you support and schools will often be one or the other. It's not so bad now but it was in the 80s and 90s. Most people grow out of it when they realise just how stupid it is. Especially when you have people claiming to be protestant or catholic but instead of going to church on a sunday, they're away to the football to fight each other. You can read more about it here:
Old Firm - Wikipedia, the free encyclopedia
But you're right, Scotland is a weird weird place but it's home and I wouldn't have it any other way.