1. A chav is a inslting term used for someone who is at the lower end of the socio-economic ladder, a chav can be black, white, Asian, any ethnicity, and is not associated universally with holding far-right views.
Oxford English dictionary describes a Chav as: a young lower-class person typified by brash and loutish behavior.
2. Skinhead:
A young man of a subculture characterized by close-cropped hair and heavy boots, often perceived as aggressive.
The latter has taken an identity of its own after the punk era, again skinheads are not all racists but most racists use the skinhead attire and sub culture and have adopted it for themselves. This includes militant groups such as Combat 18:
Skinheads can be identified more often than not by their tattoo sleeve or boot lace color:
White: White Pride
This is often used to represent Ku Klux Klan affiliation, as well. Often times the two go hand in hand. Fun anecdote about the difference between KKK members and Neo-Nazis: the KKK refuses to associate with the beliefs of Hitler, because he was foreign, and they hate foreigners. That's right folks, the Ku Klux Klan's hate is American made, and accepts no substitutions.
Blue: Killed a Cop
The scariest thing to me is that these shoelaces indicate not just murder of a police officer, but the fact that they're openly bragging about it, and that it's so prevalent that there's a code for it.
Red: Neo-Nazi/National Front
Could also mean always up for a fight, or that they've killed someone. These are apparently the meanest SOB's you'll come across, and it's advised that you don't associate with them.
Yellow: Anti-Racist
Thankfully, since Docs often come with yellow laces, they haven't been given an assigned meaning. The anti-nazi punk movement claimed a few lace colors, and this is one of them.
Purple: Gay Pride
An interesting one. Purple laces are anti-skinhead, but also often mean gay pride. This has nothing to do with the others, but I think it's worth noting.
Black: No Affiliation
Another good thing to know is that black laces (another standard Doc lace) don't have a meaning either.
Hope you understand now!