Earlier quoted context omitted.
It was about brown people. Always is. They aren't bothered by white immigrants.
Kinda. I think it's slowly becoming more anti immigration in general. Though with the London Mayoral election on Thursday, it seems like people want Khan out, using "ULEZ" as the excuse for not wanting a "brown" person. I know a fair few people who live in London and their only criticism of him is ULEZ, even if it doesn't effect them at all (massively brainwashed by Facebook)
Looks like concerns around ULEZ were way overblown, given Khan's comfortable win. A lot of noise drummed up by a small minority of fruitcakes on social media.