Photosynthetic pigments


Photosynthetic pigments convert light into biochemical energy. The most efficient photosynthetic pigment on Earth is chlorophyll, which reflects green light. But chlorophyll is not the only photosynthetic pigment, and there are at least six different types of chlorophyll, each a different shade of green.

The absorbance spectrum of chlorophyll closely matches the solar spectrum, filtered through a N2/O2 atmosphere. This close match is what makes chlorophyll the most efficient photosynthetic pigment on Earth. However, on a planet orbitting another star, the stellar spectrum will be different. On that planet, other photosynthetic pigments maybe more efficient than chlorophyll. So the leaves of healthy plants on an extrasolar planet might not be green. They could be orange, yellow, red, brown, blue or purple, depending on the stellar spectrum, the planets atmospheric constituents and the length of a day. The following is a short list of known photosynthetic and light-harvesting pigments.

PigmentColour
Allophycocyaninpurple
Antheraxanthin
Apocarotenalorange/red
Astaxanthinred
Bacteriochlorophyll apurple
Bacteriochlorophyll bpurple
Bacteriochlorophyll cgreen
Bacteriochlorophyll dgreen
Bacteriochlorophyll egreen
Bacteriochlorophyll ggreen
Bacteriorhodopsin
Canthaxanthinpink/red
a-Caroteneorange
b-Caroteneorange
e-Carotene
g-Caroteneorange
t-Carotene
Chlorophyll ayellow-green
Chlorophyll bblue-green
Chlorophyll c1green
Chlorophyll c2green
Chlorophyll dgreen
Chlorophyll egreen
Cryptoviolin
Diadinoxanthin
Diatoxanthin
Dinoxanothinyellow
Flavoxanthinyellow
Fucoxanthinyellow
Luteinyellow
Lycopenered
Neoxanthin
Peridininyellow
Phaeophytingrey
Phycocyaninblue
Phycoerythrinred/brown
Phycourobilin
Proteorhodopsin
Spheroidene
Violaxanthin
Xanthophyllyellow-orange
Zeaxanthinyellow

Colours

Visible Light400 to 700 nm (nanometers)
Violet400 to 450 nm
Blue450 to 500 nm
Green500 to 570 nm
Yellow570 to 590 nm
Orange590 to 610 nm
Red610 to 700 nm

Specific ColoursDominant wavelength (nm)
Cobalt Blue474.6
Ivory Black494.5
Emerald Green511.9
Chrome Green552.4
Manganese Violet553.7
Cobalt Violet560.3
Zinc White569.5
Zinc Yellow575.8
Chrome Yellow581.6
Raw Sienna584.2
Cadmium Orange586.9
Burnt Umber589.5
Burnt Sienna598.5
Venetian Red599.2
Cadmium Red604.8
English Crimson608.1
Alizarin Crimson628.0