> Blue was not supposed to be used on warning signs, and it faded, especially outdoors. This line gives a glimpse into how much various seemingly arbitrary as

> Blue was not supposed to be used on warning signs, and it faded, especially outdoors. This line gives a glimpse into how much various seemingly arbitrary aspects of our world are actually the way they are for good reason, and how much cultural knowledge is behind it all. Naturally, when reading this line I searched for "UV fades blue" for more info, came up with someone asking why blue fades less[0]. The depth of knowledge embedded in our culture is amazing, and the Internet is here to reveal so much of it if you look around. [0] https://www.reddit.com/r/askscience/comments/oibm9/why_is_blue_the_last_color_to_fade_in_sunlight/ https://www.reddit.com/r/askscience/comments/oibm9/why_is_bl...