Ever since 1994 there�s no substantive difference between republics, territories and regions of the Russian Federation, they have all similar rights and powers. (And the current trend reducing those rights menaces all those at the same rate.) The issue of upgrading the status of Kaliningrad Region to a Republic is thus moot since 1994, after the self rule rights (and budget) of regions and territories were raised to meet those of the autonomous republics. So, I cannot see the inherent advantage of switching from region to republic status in nowadays Russia.
As the inhabitants of the Kaliningrad Oblast' are searching for their new identity, there comes the Baltic Republican Party with the idea of upgrading the status of the enclave to that of the autonomous republic within Russian Federation. This idea is gradually gaining popular support among Kaliningraders along with the motion to return the name of Koenigsberg [Kënigsberg | Кёнигсберг] to the capital city of the wished for republic. Among supporters are influential personalities like former chairman of the Federal Council, Shumeiko and former governor of the Kaliningrad Oblast', Gorbenko. The leader of the Baltic Republican Party, Sergiey Pasko, argues eloquently that the change of the status is being made more urgent with the European Union rapidly encroaching on the borders of the enclave and the upgrading would further work for the benefits of the area and also for the Russian Federation as a whole. Baltic Republican Party proposes a new flag for the would be Republic (Baltic Republic / Republic of Baltia), which is a Russian tricolor charged with the golden compass rose. The golden compass is also an emblem of the party with superimposed letters �BRP� (�БРП�).
According to James Minahan�s Nations Without States [mnh96], the green-white-blue flag is not an official one, but is rather the flag of the Koenigsberger separatists, who seek greater autonomy for the region and to raise its status to a republic.
It was reported on pp. 198-200 of The Flag Bulletin 148 [tfb], Sept/Oct 1992, e.g. �Kalingrad Region, capitol Kalingrad (formerly Konigsberg) �...� it is now an enclave bordered by Lithuania, Poland and the Baltic Sea�. The article gives a very carefully qualified observation: �It is reported that a local flag is in use, consisting of green-white-blue horizontal stripes in a 1:2 ratio. The official standing of the flag is unknown.� Unfortunately, it does not cite a source for the reported use.
The book One Europe - 100 Nations [rpd92] suggests that the East Prussia flag is a black over white horizontal bi-colour.