[nostrademons]

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.

[adverbly]

> Nash equilibrium

Bro... Game theory laws like Nash equilibrium dont apply if the population is irrational. Which it largely is!

Good luck explaining Nash equilibrium to a baby.

[nostrademons]

You can have a system that is rational even if the individual participants are irrational. Among the mechanisms for this are statistical (if any given member of the population frequently makes errors, but the errors average out to the overall rational solution) and selection (if all the irrational people die and drop out of the population, which seems to be the case here).

[Tronchenbiais]

"Did you realise that no matter the outcome, everyone who picks red can never die? Let's all pick red and not die!"

Seems pretty easy to me.