You can vote from overseas in whatever location was your last permanent US residence.
People in DC get to vote for president because a special law was passed giving them electoral votes.
People in Puerto Rico have a US permeant residence that doesn’t let them vote for president, so they can’t legally vote from a different jurisdiction.
One of the proposals that’s come up occasionally is to make a similar law for Puerto Rico as we did for DC, but there’s never enough consensus on any plan to go forward, up until relatively recently.
The notion of getting a special edition white one, then swapping the shell to a custom black is funny.