If your hair is brown, purple probably isn't going to show up very well. It's best to bleach your hair before dying it an unnatural color. Like I told you before, the box says 30-40 minutes, but the most I'd leave it on for is an hour. And that's at your own judgment, too.
But China's population statistics can be particularly misleading. Virtually overnight, Chongqing has become the largest city not only in China, but in the world, Time Magazine proclaimed in 2005. But it wasn't true-Chongqing is not the largest city in the world, or even in China.
This year's edition of the World Urban Areas Report covers more than a thousand of the largest cities in the world, from Tokyo (pop. 37,000,000), right down to tiddlers like 850th-ranked Leicester (Pop. 534,000): all 1,009 cities, in fact, with a population of half a million of more. Here are the top 10.