Actually, some businesses offer these [1]: This seems like a good way to save both sleep & energy while preserving a good visibility. According to the page, th

Actually, some businesses offer these [1]: This seems like a good way to save both sleep & energy while preserving a good visibility. According to the page, the CRI (color rendition index) of their warm LEDs is better than conventional HPS lamps. This means that you can actually distinguish objects better with it. I have also heard of someone who patented a filter for LED lamps, but I don't know how far he got with that. In my city, we have some of these filtered LEDs installed and it feels more pleasant than any white/blue LED streetlights I've seen. [1] http://www.cree.com/news-media/news/article/next-generation-of-groundbreaking-rsw-led-street-light-portfolio http://www.cree.com/news-media/news/article/next-generation-...