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.

Pigment	Colour
Allophycocyanin	purple
Antheraxanthin
Apocarotenal	orange/red
Astaxanthin	red
Bacteriochlorophyll a	purple
Bacteriochlorophyll b	purple
Bacteriochlorophyll c	green
Bacteriochlorophyll d	green
Bacteriochlorophyll e	green
Bacteriochlorophyll g	green
Bacteriorhodopsin
Canthaxanthin	pink/red
a-Carotene	orange
b-Carotene	orange
e-Carotene
g-Carotene	orange
t-Carotene
Chlorophyll a	yellow-green
Chlorophyll b	blue-green
Chlorophyll c1	green
Chlorophyll c2	green
Chlorophyll d	green
Chlorophyll e	green
Cryptoviolin
Diadinoxanthin
Diatoxanthin
Dinoxanothin	yellow
Flavoxanthin	yellow
Fucoxanthin	yellow
Lutein	yellow
Lycopene	red
Neoxanthin
Peridinin	yellow
Phaeophytin	grey
Phycocyanin	blue
Phycoerythrin	red/brown
Phycourobilin
Proteorhodopsin
Spheroidene
Violaxanthin
Xanthophyll	yellow-orange
Zeaxanthin	yellow

Colours

Visible Light	400 to 700 nm (nanometers)
Violet	400 to 450 nm
Blue	450 to 500 nm
Green	500 to 570 nm
Yellow	570 to 590 nm
Orange	590 to 610 nm
Red	610 to 700 nm

Specific Colours	Dominant wavelength (nm)
Cobalt Blue	474.6
Ivory Black	494.5
Emerald Green	511.9
Chrome Green	552.4
Manganese Violet	553.7
Cobalt Violet	560.3
Zinc White	569.5
Zinc Yellow	575.8
Chrome Yellow	581.6
Raw Sienna	584.2
Cadmium Orange	586.9
Burnt Umber	589.5
Burnt Sienna	598.5
Venetian Red	599.2
Cadmium Red	604.8
English Crimson	608.1
Alizarin Crimson	628.0