Why isn't blood pink in the Future Arc (Mirai-hen), like it is on other Danganronpa media?
Based on a theory from Japanese audiences (source), the pink blood is only shown on school life/game (class trial) setting (e.g. DR1 and DR2).

学生じゃないからじゃね
Isn't it because they are not students already?
学級裁判とは違ってゲームじゃないって事じゃね？
Isn't it because it's different from class trial game?

As for personal theory extending from this theory, it has something to do with school life → age → &quot;censoring&quot;. Now that they have graduated (or &quot;matured&quot;) in DR3:Future, the blood is shown red, just as real life.

Note: however, some blood is (or looks like) pink in Future's OP scene.