A group recently were going through the Garfield flock to choose breeding stock for both the Whites and the Blacks. They have said that they believe the Whites come from recessive genes.
There are breeders working on Whites, Auburns, Silvers, but until more of these birds breed true consistently, it will be difficult to get the APA to consider accepting them into the standard. Whites looked too much like other white chickens so they were removed from the SOP. Apparently there are still problems with getting the Whites to have a consistent leg color and which leg color would even become the one chosen to breed to.
Perhaps Mottleds would satisfy your Java desire and solve the problem of the other black chickens being around until you can obtain some Whites.