Blue Tongue Skink Colors and Patterns

Blue tongue skink colors in the wild are muted: gray, brown, cream and pink, arranged as bands or blotches on a smooth, overlapping scaled body. The famous blue is limited to the tongue, which the lizard shows only when threatened. This guide covers the natural range, how young animals differ from adults, and what changes in captive lines.

Wild type colors

Animal Diversity Web describes the common blue tongue skink (Tiliqua scincoides) as having a grayish belly and a pale brown head. The back carries alternating streaks or blotches of dark brown and cream.

The Australian Museum gives a fuller picture for the eastern form. It is silvery gray with broad dark brown or blackish bands across the back and tail. Coastal animals often have a black stripe between the eye and the ear, which can run down the side of the neck.

Belly color stays plain in most animals, so the pattern is a feature of the back, tail and sides. Bands are the rule in this group, and they give each animal a slightly different look. Two lizards from the same litter rarely match exactly.

Blue tongue skink patterns

Blue tongue skink patterns fall into two basic types: crossbands and blotches. Crossbands are dark stripes that wrap over the back and continue onto the tail. Blotches are larger patches of pale color set against a dark ground.

The Australian Museum describes a blotched variety of the eastern blue tongue as dark chocolate brown to black. It carries large pink, cream or yellow blotches on the back, and the tail is banded in the same colors. This is a natural form, so it is not a captive morph.

The related northern subspecies is dark brown with pale crossbands, according to Smithsonian’s National Zoo. LafeberVet adds that its sides can show pink to orange. Band width and spacing vary between individuals, and a few animals have wide, nearly solid bands while others show narrow, crisp ones.

Blue tongue skink colors by subspecies and form

The table sums up what the sources reviewed say about each natural form. It does not include captive color lines, which are covered further down.

The Irian Jaya animals seen in the pet trade are treated by LafeberVet as an undescribed form of the species. No source reviewed gives a full color description for them, so this guide does not either.

Juveniles versus adults

Animal Diversity Web notes that young blue tongue skinks are more varied in color and that the variation fades as they mature. Hatchling and newborn colors are therefore a poor guide to adult appearance. A bold juvenile can settle into a plainer adult.

Newborns are small. The Australian Museum lists hatchlings at about 130 to 140 mm total length and 10 to 20 grams at birth, while adults reach close to 600 mm. Color changes happen over that growth period, so photographs of the same animal a year apart can look quite different.

Because the pattern can shift, breeders and owners should record an animal’s color at several ages. A single juvenile photo is not proof of what the adult will look like. See the species overview for size and growth details.

Male and female color

Animal Diversity Web reports that the sexes look alike. There is no reliable color difference between males and females, so color cannot be used to sex an animal. Sexing requires a veterinarian or an experienced keeper using accepted methods.

No color trait separates the sexes. The safe conclusion is that color and pattern tell you about locale and individual variation, not about sex.

The blue tongue itself

The blue tongue is a defensive signal. The Australian Museum says a threatened lizard turns toward the threat, opens its mouth wide and sticks out the broad blue tongue, which contrasts strongly with the pink mouth. The display works together with the large head to make the lizard look more threatening.

The Burpee Museum of Natural History describes the same display as aposematism, meaning a bright warning color that signals danger to predators. The tongue is not used for courtship or for camouflage. Keepers who see the tongue out are looking at a stressed or startled animal.

A 2018 study by Badiane and colleagues in Behavioral Ecology and Sociobiology measured the tongue of the northern subspecies. The rear of the tongue reflects ultraviolet and blue light at almost twice the luminance of the tip, and that UV blue is more conspicuous to birds than to other lizards.

The full tongue display appeared only in the final stage of a simulated attack, which fits a startle or deimatic display rather than a constant warning. In plain terms, the lizard keeps the brightest part hidden until escape looks unlikely, then flashes it.

Locale forms and species differences

Trade color differences often follow locale. The species has two subspecies, the eastern and the northern. Both are native to Australia, per Smithsonian’s National Zoo and Animal Diversity Web.

The Indonesian forms sold as Halmahera, Kei or Merauke are treated by the trade as a separate species, the Indonesian blue tongue. Their colors are that species’ data, not the common blue tongue’s. This guide does not use them as a color reference.

Captive color lines

Captive breeding has produced lines with reduced or altered pigment, such as lighter, paler animals and animals with little or no pattern. These are hobby names. Their inheritance is reported by breeders and has not been independently tested, and no peer reviewed, university or museum source describes their genetics.

The same caution applies to health claims about eye or skin problems in some light lines. No source reviewed for this guide supports or refutes them, so treat them as untested and ask a reptile veterinarian about any eye concern. Buyers should ask what a seller actually knows about a line, and whether breeding records exist.

For named color lines and their reported inheritance, see the blue tongue skink morph index.

Genetics terms are explained in the morph genetics guide.

How to describe blue tongue skink colors at home

1. Note the base color of the back: silvery gray, brown or near black.
2. Describe the pattern as crossbands, blotches or streaks, and note whether the tail is banded too.
3. Record markings on the head and sides, such as an eye to ear stripe or pink to orange flanks.
4. Photograph the animal in even light at several ages, because juvenile color fades.
5. Use the word morph only for a line with a documented breeding history. Natural forms and locales are not morphs.

For the wider picture on how color variants arise across reptiles, read the reptile morphs guide.

Frequently Asked Questions

Are blue tongue skinks always blue?

No. Only the tongue is blue, and it is hidden until the lizard displays it. The body is gray, brown, cream or pink depending on the form.

Do blue tongue skinks change color as they grow?

Their color fades and becomes less varied with age, according to Animal Diversity Web. Bands can stay but the contrast often softens.

Can you tell male from female by color?

No. Sources report that both sexes look alike, so color gives no clue.

Why do they stick out the blue tongue?

It is a startle display. The Australian Museum notes that the lizard faces the threat and opens its pink mouth wide to show it, and a 2018 study found the UV blue rear of the tongue is flashed only in the last stage of an attack.

Is the blotched blue tongue a morph?

The Australian Museum lists the blotched pattern as a natural variety of the eastern blue tongue. It is a wild form with dark ground color and pink, cream or yellow blotches.

Are captive color lines proven genetically?

No source found for this guide tests them. The names and inheritance modes are reported by breeders only.