Since if a rational actor would understand that the group can avoid ever dying to this game by simply choosing blue. There is no consequence for choosing blue - but there is a consequence for choosing red.
Also, regardless of these specific consequences, people who are rational/ethical will by default choose blue because it is a good color.
People's "by default" behavior will never define what is rational. You don't do polling to choose rationality.
If there is a game in which you choose between two buttons, you know everyone will get this same choice, and one button says that you definitely live and the other button says that there's a chance that you will die, adding more rules to the "maybe death button" can not make it a more rational choice.
This is actually an experiment that I would get behind doing in real life. I will pick the red button. We could do it every morning.
There are enough collective action problems with real and obvious benefits leading to catastrophe without the need to create more unnecessarily, or to have any confidence in in a world full of strangers' collective ability to solve them. Campaigning for blue is actually murder; you've encouraged a situation that may result in the deaths of 49% of the population.
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.
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).
Only irrational people will pick blue. Let's say that's ~3% of the population. Trying to get another 47% of the population to pick blue risks losing all of them as well. That's not ethical.
Also, regardless of these specific consequences, people who are rational/ethical will by default choose blue because it is a good color.
See also, people by default choose blue at 5x the rate as red, really putting a dent in "red==rational" conjecture: https://www.joehallock.com/edu/COM498/media/graphs/fav-color...
I hope this makes sense!