What are the blue reflectors on the street? What purpose do they serve?
What are those random blue reflectors that you see on US streets?
How are reflectors and refractors alike? If I look at something that's blue or red, would someone else see the same color that I see? How are refractors and reflectors alike? What does a flashing blue traffic light mean? How many colors can humans see? How can we tell if the blue I see is the same blue you see? What are those big metal grates you see on city sidewalks? Why do police vehicles only use red and blue colors for their sirens? Why are police lights red and/or blue? What is the best eyeshadow color for blue eyes? How many colours can we see? How many types of siren are there for vehicles? What do different lines and colors on the road mean in the US? Where are blue license plate lights legal? What objects reflect light? Why are police lights red and blue? What can distinguish a meaningful street photography work amongst so many images of this sort available today? What colors gives dark blue? How red yellow green colors glow in traffic signals? What do different colors signify on cop cars in the US? Could a 100% reflective mirror physically exist? What's the strangest thing you've found in the roadway? Driving in California: Where are there cameras watching for running yellow or red-lights in San Francisco? What do "blue balls" look like? Where from can I buy mirrors for reflector telescope living in Haryana? Is a photoelectric effect used in street lights? What are the coordinates for some weird things on Google Earth/Google Maps? What are some examples of "blue laws" that exist in California? I see roads on the Pokémon GO map that glow faintly and are lighter, almost white. What is that? How does the reflection of waves affect specular reflection?