If I wrote a program to find things that were grue before time t, and things that were bleen after time t, I would not save any time on the programing by making it just look for green. Green could not be coherently defined without committing to observers, but grue could be defined (even if very complicatedly) without reference to observers, and thus we can be realists about it. I am a realist about grue, and not about green. THis makes sense since green requires observers in its definition.

Meanwhile, in a parallel universe, grue-potato wrote this, and grue-taw is trying to make him see that green is just as consistent.