The people who chose blue in no way contributed to the peril you are in, thus you aren't justified in killing them in self defense.
They didn't cause the peril, but knowing that their choice is possibility, if I don't make a decision to protect myself now their decisions may then be the cause of my continued not-survival.
They didn't cause the peril, but knowing that their choice is possibility, if I don't make a decision to protect myself now their decisions may then be the cause of my continued not-survival.