1. "Darlie" is a brand of toothpaste readily available in China,
2. 黑人牙膏 means "black people's toothpaste", (the picture of the Black and White Minstrel was a dead give away wasn't it!)
3. The company has, perhaps wisely, changed the English name of the product to Darlie Toothpaste. It was previously known as Darkie Toothpaste.
See also: http://www.wholepop.com/features/oral/strange.html