What tooks Apple so long to make White iPhone 4?

Have you ever wonder why it tooks so long for Apple to make this gorgeous White iPhone 4 which finally available today? According to The Wall Street Journal’s Mobilized blog, white iPhones need
UV protection. Author Ina Fried interviewed both Apple’s boss Steve Jobs and marketing honcho
Phil Schiller. The latter said:

It was challenging. It’s not as simple
as making something white. There’s a lot more that goes into both the material
science of it–how it holds up over time…but also in how it all works with the
sensors.

And here is from Jobs :

We obviously think about this in a
generic way because you have a white iPad.

Steve Jobs also confirmed that an upcoming iOS update will address that location
tracking issue that Apple earlier today characterized as a “bug” and confirmed
Apple will next week testify in a Congress hearing about location-gathering
practices.