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.
The world's largest cities are huge! The world's largest urban area - Tokyo (37.8 million) - has a larger population than the entire country of Canada (35.3 million). Below you'll find a listing of the world's largest urban areas, known as urban agglomerations, based on data compiled by the United Nations Population Division. The data on these 30 largest cities of the world is current as of 2014 and reflects the best possible estimates of the populations of these huge cities.