Apple is typically close-mouthed about problems in today’s Statement on White iPhone 4

White models of Apple’s new iPhone® 4 have continued to be more challenging to manufacture than we originally expected, and as a result they will not be available until later this year

What could be more challenging to manufacture about the color white? I am certain some will see this as an antenna redesign moment. Apple probably intends it to be taken that way. The device is glass so color really should be a non-issue. More to the point, glass is very fragile so I sincerely doubt this has anything to do with white being a more fragile color than black. Will white be the iPhone4.1?

Engadget says no, it really is just a paint issue. The problem is related to getting the appearance right:

…the factory’s still working out the perfect combination of paint thickness and opacity — the former to ensure the next sub-contractor has enough clearance for the digitizer overlay, and the latter for the absolute whiteness that Jony Ive and co. strive for