There is no reflected light, so we see black (the absence of color). Black objects absorb all the light shined on them. In each case we are seeing the complementary colors to the ones absorbed.īy looking at the absorption spectrum and complementary colors for chlorophyll we should be able to predict that plants look green.īlack and white objects are just the extremes of colored objects. Ultraviolet-visible (UV-vis) spectroscopy is used to obtain the absorbance spectra of a compound in solution or as a solid. When sunlight is shined on a green leaf, the violet, red and orange wavelengths are absorbed. The transmitted light is the light we see, and it looks orange.Ĭolored objects look the way they do because of reflected light. What this all means is that if a particular colour is absorbed from white light, what your eye detects by mixing up all the other wavelengths of light is its. When sunlight shines through an orange solution, the violet, blue and green wavelengths are absorbed. The test tube in the figure contains an orange solution. Objects like this are called blackbody radiators.Ĭolored liquids or solutions look colored because they absorb some of the light shined on them.

It looks white because it is emitting at least some of all the wavelengths in the visible region. If someone shined white light at us, what wavelength does it have? White is not in our visible spectrum because it is composed of all the wavelengths of light. Violet is the most energetic color and red is the least.Īccording to the figure, if someone shined light with a wavelength of 550 nm at us it would look green. Note that these are in reverse order on the figure below. The acronym 'ROYGBIV' helps us to remember the colors of red, orange, yellow, green, blue, indigo and violet. Excited states formed from energy absorption are short-lived because the electron seeks the position of lowest potential energy and the. While a materials apparent color is most often the result of absorption of light, color can also arise from emission of light. The different wavelengths within the visible region are responsible for the different colors we see. By viewing an absorbance spectrum, the color that absorbs can be determined.

Color absorbance spectrum