I just finished watching a segment on NHK and there was an aerial view of a town or part of a town and most of the structures had grey or charcoal roofs except a fair number scattered around with the same color of blue roof.
What do the blue roofs mean? E.g., are they government or medical buildings, and are they intended to be seen by aircraft? This segment was about air ambulances.
https://www.reddit.com/r/japan/comments/14iebra/what_is_the_meaning_of_blue_roofs_on_buildings/
5 comments
There is a law in Japan where if you are super attracted to anime characters, you have to have a blue roof. Weird but true!
If the roofs are blue, it means they’re 青色. That way, you can tell them from roofs that are 赤色 or 灰色.
They are probably just older tin roofs. Blue and red have traditionally been the most popular colors for tin roofing.
There was a brief fad for blue ceramic tile roofs as well, but blue tiles don’t wear very well so they aren’t as popular anymore.
There’s no magical roofing color code in Japan. Roofing colors are decided in the same way as they are anywhere else: by preference and availability of materials.
Blue roof tiles were apparently trendy at one point. I found a [few](https://kamisei.co.jp/news/763) [sites](https://roof-kadoma.com/blog/hukikaekouzi1802081010.html) [that](https://showa-yougyo.blogspot.com/2017/09/blog-post_29.html?m=1) point to them being popular from roughly the 1960s to the 1980s; I definitely get strong Showa vibes from them.
Case in point: blue tiles and roofs can be found on [Shūwa Residence](https://www.timeout.jp/tokyo/ja/things-to-do/shuwa-residence) [buildings](https://japanpropertycentral.com/2011/08/shuwa-residence-series-of-vintage-apartments/), an iconic, Western-inspired style of apartment block that popped off from the 60s-80s in Japanese cities.
If it’s dark blue it could be solar panels.
But I think I know the relatively light blue you mean. Pretty sure it’s just a popular roof colour.