These are so intensely annoying.
Besides the obvious choice of not pushing any button, so very rarely -- if at all -- are there only ever 2 options. The entire "thought experiment" leans into some fantastical unrealistic scenarios and plays on peoples "fast thinking" by saying here are 2 options I made up, tell me which of these 2 groups (us or them) shall I sort you into? Neither.
I thought about the ternary choice. Unconscious people, conscientious objectors, etc. The wording is that blue needs to exceed 50%, so the doomsday machine defaults to red.