4 ms·

I thought the question was asking whether there are any reds that are blue. Edit: This isn't as clear as it could be if I was better with GIMP, but it should i

• redial 8y ago
  The question is "are" there any blue reds. In other words, regardless of who is watching it, or if anyone at all. The question is not "can we perceive" some reds as blue.
  • mcbits 8y ago
    There are no blues or reds at all if nobody is watching. Color is a purely perceptual phenomenon relying on properties of the eye and brain.
    • redial 8y ago
      Not true, what we call the color red is an electromagnetic wave with a wavelength between, according to wikipedia, 625 and 740 nanometers. And if you are looking at a picture on a computer, the computer will call red a pixel with an rgb value of (255, 0, 0) even if nobody is looking at it.
      • mcbits 8y ago
        The light coming from the car in that image would be concentrated around 450-500 nm, not 625-740 nm. Viewed in isolation, that's blue, but in the context of the rest of the image, it is red. The "redness" of the car exists only in the brain of the viewer, which has evolved to produce stablility of color in a variety of lighting conditions. That's also why RGB monitors display more than three distinct colors. The colors are synthesized in the brain. If we were orbiting a brown dwarf, we might talk about colors within the infrared part of the spectrum as if they were intrinsic properties of light.