Azure Demon Mask

The main thing is in Japan, they refer to green as blue in a bunch of cases. (Ex. the green man to cross the street is normally referred to as blue) It's just a culture thing and you really should just ignore it.

Yeah, I noticed that as well. Even its Japanese name "The turquoise color Face demon" (based off a translation website) seems a bit off because its color is more of a regular green instead of turquoise (a greenish blue color). I feel that "Emerald Demon Mask," "Vert Demon Mask," or even "Green Demon Mask" would have been better name choices.

huh.

A more specfic explanation for it is that in japan green is considered to be a shade of blue rather than a completely seperate color. So the same word is applied to both in most case. They do have a seperate word to define green ibut it's a much more recent addition to the language so not as widely used.