So far, I’ve assumed that they ended with these plastics, with the logo on the front. Before that, they were using green boxes, some time after the Altos were added; the logo was on the back on those. Before that, there was no colour-coding, with the Soprano having a red box. Going back even further, there was not even a “Soprano” on the box.
Mysha replied to the topic Does anyone play the melodica for reasons other than the sound? in the forum General melodica discussion 4 weeks ago
Melodicas Hohner Soprano and Alto are narrow enough to be played left-handed, and they actually play where your attention is.