What color is it?

i was having a discussion about color with k2h (specifically talking about the range of the UV-vis spectrometer that was in an advertisment). something often forgotten (or never known) is that your monitor cannot display all the colors we can see because we use red, green, and blue as the primary colors (see hyper-physics and color cell.org). other primary colors are possible, but since those are the colors that our eyes use in the cones makes sense to use those colors for monitors. an interesting thing about color is what you see isn't necessarily what you are getting. for instance pink has no wavelength that corresponds to it, but we still see it when the light reaching our eyes matches the right spot on the cie diagram. in science, we frequently forget out purple and pink and talk exclusively about the wavelength colors. the spectrum is then red (625-740 nm) orange (590-625 nm) yellow (565-590 nm) green (520-565 nm) cyan (500-520 nm) blue (435-500 nm) violet (380-435 nm) [note: indigo is not in the rainbow and cyan is probably since we use it in printing CMYK]. so why did i list it starting with red instead of violet? two reasons: 1) we always start with red when listing the colors as children, or at least i did 2) the light with longer wavelengths (red) has lower energy and short wavelengths (blue) higher energy. people give off infrared light because we don't give off much energy in our black body radiation, however the sun gives off higher energy and thus covers more of the spectrum and through scattering and absorption of the atmosphere we end up with somewhat equal amounts of each light. here's a the path black body radiation takes as an object heats up plotted on a cie diagram. and if you've ever wondered what being color blind means... check out the super fun page here, its fun to play with even on a simple page like google.

oh ya... and what does cie stand for? International Comission on Illumination of course. the french (?) probably helps you out more for the letters Commission Internationale de l'Eclairage.;
and the rainbow picture was shamelessly used without permission from the blogInformatics, Chemistry & Life in General, which actually showed up in google images on the forth page of rainbow searching.