What kind of self dye are you talking about?

浸染or热升华？I think 浸染is different than dye-sub keycaps,
浸染involve boiling the keys in chemical that etch the whole key with color,
and dye-sub is involving baking the key to a certain temperature to melt the color into the key surface.

two completely different procedure have very different outcome.
浸染because is etched, it turned dirty due to the surface micro etched holes.
while dye-sub keycaps doesn't have this problem.

ya, that's what I was saying.
you can try search 热升华 instead, that is dye-sub.