>>4660462There have been several studies on British DNA. Here is the most recent one:
http://journals.plos.org/plosgenetics/article/authors?id=10.1371/journal.pgen.1007152Now, admittedly there haven't been any tests to check how non-white native Brits are, because that would be preposterous. There's no evidence that that's the case, and the British population has been extensively genetically mapped.
With the US and other New World populations, it's hardly surprising, as they were in contact with large non-white populations for a long time. This is not the case in Britain. I must also point out that sensationalist and rare occurrences such as this make for better news than: "white person finds out they're white". And the statistic that you mentioned, i.e. "Only 80% of whites are fully white is bogus, as this article mentions":
"a 2014 study of 23andMe customers found that around 5,200, or roughly 3.5 percent, of 148,789 self-identified European Americans had 1 percent or more African ancestry"
So a tiny minority of American whites, and even then 1% non-white DNA is basically insignificant (as well as a possible statistical error).
