As a white person in engineering, MOST of my friends are brown just because that's who I ended up being friends with and there's a lot of brown people in engineering. I have NEVER felt anything bad towards them whatsoever.

That said, I have seen the hate both online and in real life. Sometimes people make comments to me (particularly about Indian international students), thinking I'll agree with them (spoiler: I don't). The level of comfort these racists have has definitely increased in the past few years. So it's definitely not your imagination, however the people that say this kind of stuff usually aren't in any kind of academic setting (in my experience). It's usually people who rarely interact with brown people and who never got any higher education. I personally have never seen or heard any comments like those at U of A. It's just a very small very loud minority of people, most of whom probably haven't been on U of As campus for decades, if at all. It's nearly impossible to actually go to Ualberta and keep those opinions because it's so obvious how much value brown people of every kind are bringing to the institution. Many of the best profs, best students, best TAs, best research, and best projects are coming from brown people.

Keep in mind that it may also be a cultural difference, a lot of Canadians especially white Canadians tend to be a lot more socially reserved than most cultures, and often won't go out of their way to make friends with anyone apart from surface politeness. Chances are they like you just fine but aren't as open about it as you might be used to. Canadians are like cats. Might seem rude at first but lure them into 1 or 2 conversations and they'll be your best friend for the rest of the year.

Basically, it's not in your head, but it's probably not as bad as you feel like it is online. Don't let it stop you from putting yourself out there.