Mark Moffett / Strawberry Poison Dart Frog (Oophaga pumilio) group showing color variation from different islands, Bocas del Toro, Panama

Fred Bavendam / Common Comet Star (Linckia guildingii) in an unusual lavender color variation, it is typically beige or yellowish in color, Manado, North Sulawesi, Indonesia

Duncan Murrell / Green garden lizard (calotes calotes) showing color variation, Deniyaya, Sri Lanka.

Franco Banfi / Golden grouper (Mycteroperca rosacea), yellow color-variation of the most common leopard grouper species, Cabo Pulmo Marine National Park, Baja California Sur, Mexico

Franco Banfi / Golden grouper (Mycteroperca rosacea), yellow color-variation of the most common leopard grouper species, Cabo Pulmo Marine National Park, Baja California Sur, Mexico

Chase Dekker / Red Fox (Vulpes vulpes) kits, Washington

Chase Dekker / Red Fox (Vulpes vulpes) kits playing, Washington

Chase Dekker / Red Fox (Vulpes vulpes) kits at den, Washington

Rod Williams / Jersey tiger moth (Euplagia quadripunctaria) with less common yellow colour variation feeding on ragwort, Lewisham, London, UK, August.

Tim Fitzharris / Gray Wolf (Canis lupus)group with submissive licking dominant wolf, Montana

Mark Raycroft / Labrador Retriever (Canis familiaris) trio

Mark Raycroft / Labrador Retriever (Canis familiaris) trio in water

Mark Raycroft / Labrador Retriever (Canis familiaris) trio in water

Christian Ziegler / Left to right, from top: Nymphalid Butterfly (Mechanitis sp), Orange-spotted Tiger Clearwing (Mechanitis polymnia), Nymphalid Butterfly (Hyposcada sp), Tiger Heliconian (Heliconius ismenius), Nymphali...

Thomas Marent / Ebony Leaf Monkey (Trachypithecus auratus), golden color variation, mother with baby, Java, Indonesia

Thomas Marent / Ebony Leaf Monkey (Trachypithecus auratus) golden color variation, Java, Indonesia

Thomas Marent / Ebony Leaf Monkey (Trachypithecus auratus) golden color variation on liana, Java, Indonesia

Thomas Marent / Ebony Leaf Monkey (Trachypithecus auratus), golden color variation, mother with baby, Java, Indonesia

Pete Oxford / Palmar Treefrog (Hypsiboas pellucens) pair on leaf showing color variation, northwest Ecuador

Norbert Wu / Leaf Barnacle (Pollicipes polymerus), a colorful variation of the goose-neck barnacle found only in Nakwakto Rapids and a few other places, Vancouver Island, British Columbia, Canada

Norbert Wu / Leaf Barnacle (Pollicipes polymerus), a colorful variation of the goose-neck barnacle found only in Nakwakto Rapids and a few other places, Vancouver Island, British Columbia, Canada

Michael Durham / Domestic Chicken (Gallus domesticus) chicks showing genetic variation used to bring out traits that help poultry producers

Mark Moffett / Strawberry Poison Dart Frog (Oophaga pumilio) group showing color variation from different islands of Bocas del Toro, Panama

Mark Moffett / Strawberry Poison Dart Frog (Oophaga pumilio) group showing color variation from different islands of Bocas del Toro, Panama

Jane Burton / Domestic dogs (Canis familiaris), Chocolate brown Labrador with Golden Retriever bitch and their 6 black and white pups.

Ingo Arndt / Heliconia Butterfly (Heliconius antiochus) specimens in Inbio collection showing color variation within the species, Costa Rica

Pete Oxford / Betsileo Reed Frog (Heterixalus betsileo) this frog has variable color morphs ranging from white to green and commonly seen in gardens around Antananarivo, central highlands, Madagascar

Konrad Wothe / Snow Goose (Chen caerulescens) and blue Snow Goose (Chen caerulescens) color variation flying during migration, Bosque del Apache National Wildlife Refuge, New Mexico

Mark Raycroft / Akita (Canis familiaris) pair sitting

Mark Raycroft / Akita (Canis familiaris) pair

Mark Moffett / Weaver Ant (Oecophylla sp) group, with two color morphs, fighting vigorously, Cameroon

Mark Moffett / Shield Toad (Brachycephalus sp) pair fighting, endemic to the Atlantic Forest, Brazil

Heidi & Hans-Juergen Koch / Domestic Cattle (Bos taurus) calves nuzzling, northern Germany

Konrad Wothe / Red Fox (Vulpes vulpes) mother in cross-phase coloration with begging kit, North America

Konrad Wothe / Red Fox (Vulpes vulpes) and Cross Fox meeting, an example of color variations within a species, North America

Chris Newbert / Merlet's Scorpionfish (Rhinopias aphanes) rare coloration, 60 feet deep, Papua New Guinea

Konrad Wothe / Yellow-eyed Penguin (Megadyptes antipodes) group with two albinos, Enderby Island, Auckland Islands, New Zealand

Tui De Roy / Red-footed Booby (Sula sula) brown morph nesting in Mangrove (Avicennia sp), Tower Island, Galapagos Islands, Ecuador

Flip Nicklin / Dall's Porpoise (Phocoenoides dalli) true color variation, harvest from Otsuchi harpoon fishery, Northern Honshu Island, Japan

Mark Moffett / Strawberry Poison Dart Frog (Oophaga pumilio) dominant male wrestles and pins another male, Bastimentos Island, Bocas del Toro, Panama

Mark Moffett / Strawberry Poison Dart Frog (Oophaga pumilio) dominant male wrestles with and pins another male, Bastimentos Island, Bocas del Toro, Panama

Tui De Roy / Black Tomtit (Petroica macrocephala dannefaerdi) all-black endemic color variation, Snares Islands, New Zealand

Mark Moffett / Leaf Beetle (Stolas sp) pair showing color variation, Panama

PREMAPHOTOS / White lipped snails on moss (Cepaea hortensis) showing variation in shell markings within the species, UK.

Anup Shah / White Bengal tigers play fighting in water {Panthera tigris} India

Chase Dekker / Red Fox (Vulpes vulpes) kits playing, Washington

Heidi & Hans-Juergen Koch / Kingsnake (Lampropeltis sp) group with different colorations, native to North America

Heidi & Hans-Juergen Koch / Kingsnake (Lampropeltis sp) group with different colorations, native to North America

Tui De Roy / Burchell's Zebra (Equus quagga) in the back and Grevy's Zebra (Equus grevyi) drinking at waterhole, Lewa Wildlife Conservation Area, Kenya

Joel Sartore / Photo Ark / Two Gray sand stars, showing varying color morphs. (Luidia lawrencei) the larger, solid colored starfish on the left and (Luidia clatherata) the smaller starfish with lines, on white background, Gulf...

Joel Sartore / Photo Ark / Two Gray sand stars, showing varying color morphs. (Luidia lawrencei) the larger, solid colored starfish on the left and (Luidia clatherata) the smaller starfish with lines, on black background, Gulf...

Nigel Cattlin / A mating pair of Harlequin ladybirds (Harmonia axyridis) on apple leaves damaged by leaf-curling aphids (Dysaphis sp.). Two colour variations. Berkshire, June