[redial]

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]

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.