Concept blue color contains green?

Why green colored signal is called Blue light in our country? Though I have never been asked this question till I come across this questionnaire, I wondered it myself several times. So, this is the best opportunity to make it clear removing stubbornness from my heart. As is often the case, so many opinions were dictated  there in the Website,  no shortage of information I was looking for even on the trifles like this was observed. I had some hard tasks to find out and to  get a reprinted paper in my specialized field, but now it is possible to do the same or more in very short period of time.

It's an incredible situation half a century ago, just like a paradise to be able to access into any library in the world and to be replied in turn without delay. I feel like I am an actor playing a Paradise Dragonfly in Heaven, because I can access to anyplace, anytime even in the middle of the night whenever I want so far as Internet connection is established. Information and knowledge can be collected endlessly, personal logic can be freely developed without restrictions and transmission could be widely spread to the world if it is written in English. Getting older I feel the time passes so fast and quick and the Website accererates it.

Returning the topic that green signal as Blue light, the color of signal was dictated as green color in our Decree in 1930, but newspaper introduced it in Blue light and the dictation in Decree followed it. This is the oldest historic story of the relations between green and blue in our country. While Mannyo period about 1,500 years ago, the example to have described blue color as green is recorded, cf. "Aoniyoshi---". So, in ancient Japan, Blu contained two conceptions both blue and green, and later as the word matured some separation phenomena happened.

Even now two concept coexists in our country, Blue contains both colors blue and green. On the other hand, in English word "hoewen" has also two understandings of both blue and green colors. There might be some possibility to be called Green Safety Signal in future. As for my opinion, judging from an actual inspection, most of the traffic intersection signals were replaced into LED system and the color of blue one is blue now regardless of whether it is on or off. There may be some people in the administrative organization who are aware of the color differentiation.