Spectrum Scans
What we see as white light is actually made up of light of different colors. The figure to the right represents the visible spectrum.
![spectrum.gif](media/spectrum.gif)
Coca Cola is not "clear" but has a distinctive color to it. Using a scanning spectrophotometer we can "see" in a more exact way what color Coke is. Coke absorbs more light in the blue end of the spectrum than in the green and red areas.
![cocacola.gif](media/cocacola.gif)
![blue.gif](media/blue.gif)
This is not a perfect filter, letting some light through in the "Red" region, but it will work for our purposes.