That's one of the reasons why I decided not to reveal anything about myself on my channel. Everyone has prejudices and whether people want to believe it or not, people will dislike you based on your race/age/appearance/etc. and that's bad for business (as a youtuber and other businesses..). Even if they liked you before, their opinion will suddenly change. I think it's better not to reveal any information about yourself at all, that way there is less for people to judge.
I know you're not offended though and yes, that was obviously a troll. Most people won't even say anything.
If you're interested to finding more racist comments on youtube, watch prank or fight videos involving certain races. Those videos are flooded with pages upon pages of racist comments that you would not believe. Or maybe you will believe it, because this is what people do on the internet.. :/