>>33165657The Pikachu tail thing is completely explicable, though.
Sugimori's original Gen I watercolors used white space for highlights. The tip of Pikachu's tail was among the highlighted areas in its art.
So, your brain remembers the tip of Pikachu's tail as being different from the rest of the tail. But it doesn't remember a different hue there. In trying to fill this blank space, it draws--quite logically--from the tips of Pikachu's ears. After all, they're the only other real protrusions from the Gen I art, so it makes a certain kind of sense that, if their tips had a different color than their lengths, the tail's missing tip-color would match theirs. Pichu's black tail serves as corroborating evidence for this logic and deepens the fiction.
Looking at Pikachu's Gen I sprite, however, reveals exactly how awkward it would have looked if the tip were black. It's not just a matter of a color being changed on you sneakily--the shading of the entire tail would have to be different, which would probably necessitate a different pose.
