I love designing visualizations as a way to explore different topics. Any time I get interested in something, I look for a way to visualize it to help me understand it better.
I recently did a quick search on car lighting colors. I had a minor accident years ago when I misread dim brake lights as tail lights. It was my fault (sorry, Tommy!), but it’s bothered me ever since that these two very different messages — “My headlights are on” v. “I’m not moving” — are communicated by shades of the same color.
Ultimately, I found a PDF detailing European regulations (the American version wasn’t freely available). The European document didn’t go into the reasoning behind each color choice, but I still thought it would be interesting to catalog the options.
Top hemisphere — Front-facing lamps /// Bottom hemisphere — Rear-facing lamps /// Vertical spheres — Side lamps
Where more than one color is shown in the same location (ex. #3 Front Fog Lamp) either color is acceptable. If there are two colors in different locations (ex. #13 Parking Lamp) both are part of the regulations.