As Overland Mail's indebtedness to Wells Fargo climbed, Wells Fargo became increasingly disenchanted with Butterfield's management strategy. In March 1860, Wells Fargo threatened foreclosure. As a compromise, Butterfield resigned as president of Overland Mail, and control of the company passed to Wells Fargo.
It turns out that virtually no light with wavelengths longer than 690 nm is converted or captured by chlorophyll or carotenoids. Also, some light of shorter wavelengths than what humans can see is used by photosynthesis. Chlorophyll-a, chlorophyll-b and carotenoids all use light of wavelengths shorter than 390 nm. Interestingly, Chlorophyll-a can use light with wavelengths as short as 350 nm. This is getting into the UV or ultraviolet (above or beyond violet) range. For practical purposes, photosynthesis in general utilizes wavelengths of light from about 380 nm to 690 nm.
Photosynthesis is responsive to certain wave lengths of light energy (see Fig. 7.3, 7.4 & 7.5, Pg. 110-111 in text). The visible spectrum, from Red to Violet light is effective in photosynthesis The most effective colors of light energy are in the Red and Blue/Violet range of the color spectrum.