White iPhone 4, spotted in NYC, is not ready for sale because of mismatched colors

So when a white iPhone 4 was spotted in New York City at a press event, it was only natural to inquire how this particular owner managed to get a unit for himself. It appears that the nameless white iPhone 4 owner managed to get one though a friend that “fixed him up.” Additionally, it is found that Apple is just having some technical difficulties in ironing things out in the Far East with two of its suppliers. Specifically, the white colored home button apparently doesn't line up with the same tone of white used for the front place – so hence then delay.
If there's one thing that Apple is known for with their products, it has to be consistency – from both the inside and out. So when two parts don't necessarily have the same exact color tones, it's only fitting to get it corrected; even if it means pushing off a release.
Apple iPhone 4 Specifications | Review
source: pocket-lint