I've taken the test multiple times, and ended up with my boundary being both greener than >70% of the population and bluer than >70% of the population in separate attempts. And I know my color perception to be good at distinguishing hue - it's just that I don't have strong opinions about categorizing it in this space.
I'm pretty sure there's some hysteresis going on - if we randomly end up in the ambiguous zone on the bluer side, we'll be pressing "blue" every time a small change happens, because it's basically the same color. Until the changes add up so much that we're out of the ambiguous zone on the green side - and now our "border" is far on the green side. But if we started on the other side, entering the ambiguous zone from the green side, it'd take a big cumulative change before we press "blue".
"but does it only make these because there already exist hundreds of examples and tutorials? fear not, there's an entire library of other projects it made all of which also have hundreds of examples and tutorials"
don't get me wrong, it's interesting, but the response here didn't answer the question
Fair enough. Still up to 50 board states that can influence the current one (the 50 move rule is coming to help here)
FEN doesn't store previous states, but EPD can. It just goes to show how meanings and requirements change depending on context, which is super interesting in and of itself :P
There are two more things that should be considered.
Both of them unlikely to influence a position, but they can matter - just like the en passant target.
The fifty move rule[0] is quite simple, just store a number, fits in five bits. But the threefold repetition rule[1] is quite a pickle - it basically means that to know everything about a position you need to know every position that occurred before it.
I'm pretty sure there's some hysteresis going on - if we randomly end up in the ambiguous zone on the bluer side, we'll be pressing "blue" every time a small change happens, because it's basically the same color. Until the changes add up so much that we're out of the ambiguous zone on the green side - and now our "border" is far on the green side. But if we started on the other side, entering the ambiguous zone from the green side, it'd take a big cumulative change before we press "blue".