just buy a tactical colour....not much else you can do really,if you have a decent rucksack already but its a bit "loud" then get an olive green/camo or black raincover.....you look like quasimodo anyway humping a bergen i dont think rocking the mobile tree look is going to do you much good and if you were out hunting you'd cache your bergen with the group.
have seen reversible rain covers giving two option's
have seen reversible rain covers giving two option's
Nothing is fool proof for a sufficiently talented fool!!!!