The green I-94W (visa waiver) form is what the ESTA has replaced. The ESTA website does its best to re-implement the I-94W in exact detail, right down to the ba

The green I-94W (visa waiver) form is what the ESTA has replaced. The ESTA website does its best to re-implement the I-94W in exact detail, right down to the background colour. For the first couple of years they ran the system in parallel -- ESTA was a legal requirement, but because the systems weren't integrated they kept handing out the old I-94W's. Now they've spliced it all together the paper forms are no longer required. The white customs declaration is still used, though. And I suspect it'll stick around for a very long time (because the precise details change for any given traveller on any given flight).