There are two globally optimal solutions to this problem: > 50% pick blue (saving everybody), and 100% of the people pick red (saving everybody).

There is only one Nash equilibrium, which is for everybody to pick red. This is also strictly dominant for each player (if they choose red, they have a 100% chance of surviving, while if they choose blue, they only survive if > 50% of other people also choose blue). Knowing this, every participant has an incentive to choose red.