Gecko Colors: How Geckos Get Their Colors and Patterns

Gecko colors range from the gray and red spotted tokay to the bright green and blue day geckos. No single answer covers the whole group, because a gecko’s look depends on its species, age and sex. Most wild geckos are muted browns, grays and tans because they hide on bark, rock and leaf litter.

What color is a gecko?

There is no default. Researchers scored the dorsal pattern of 439 gecko species and sorted them into four groups.

Source: Allen et al. 2020, Evolution, 439 of about 1,744 gecko species. The authors inferred that the ancestral gecko was nocturnal and either spotted or banded.

The same study found that nocturnal lineages gain bands at elevated rates. The likely reason is camouflage, since bands break up the outline of a resting gecko. Spotted species rarely switch between open and closed habitats, while plain and striped lineages switch more readily.

How geckos make their colors

Gecko colors are built in layers of skin cells called chromatophores. Melanophores hold dark melanin, xanthophores give yellow and erythrophores give red. Iridophores contain guanine crystals that reflect light, so they create white, blue or shimmer through structure, not pigment.

The best studied example is the day gecko genus Phelsuma. In five species examined in 2013, yellow or red pigment cells sat on top, iridophores in the middle and melanophores at the bottom. Blue comes from ordered layers of guanine nanocrystals, and green appears when yellow pigment filters it.

A white belly comes from disordered crystals that scatter all wavelengths. Red comes from pteridine pigments, which change with acidity and oxidation in lab tests.

These results describe Phelsuma, but the same layering turns up elsewhere. In the tokay, red spots are patches where pteridine filled erythrophores sit on top, and the blue gray body is skin where iridophores form the top layer over a single sheet of melanophores (Szydłowski and colleagues, 2017).

The leopard gecko is different. Its normal skin holds melanophores plus yellow and red pigment cells, and the same research group reports that healthy leopard gecko skin lacks iridophores. That is why its wild colors are yellows, browns and black rather than blues.

Gecko colors and patterns by popular pet species

The table lists the natural look of the geckos most often kept. Each species has its own guide for detail.

Sources: Animal Diversity Web accounts and Saenko et al. 2013 for Phelsuma.

Tokay gecko

A wild tokay is gray with brownish red to bright red spots. Males are more brightly colored than females, and the skin can lighten or darken to blend in. The full breakdown is in the tokay gecko colors guide.

African fat tailed gecko

Wild animals are brown or tan with light and dark blotches or broad bands, and some carry a white stripe from the head down the back and onto the tail. That stripe is natural variation. See the gecko group overview for how it compares with other species.

Leopard gecko

The wild leopard gecko is yellow with irregular black spots on the back and a white belly. The tail is grayish with white crossbands and black dots. The leopard gecko colors guide covers the many captive lines.

Crested gecko

Wild crested geckos show three natural patterns: patternless, tiger and white fringed. Patternless animals are solid yellow, green, brown, red or gray, while tiger animals have dark stripes on a light background, and white fringed animals have white or yellow along the crest. Details are in the crested gecko colors guide.

Day geckos

Most Phelsuma have a blue or green dorsolateral background with red dorsal markings. One studied species, Phelsuma klemmeri, lacks red and has a blue and brown background instead. The day gecko colors guide explains the structural color in more depth.

Do geckos change color?

Some do, but usually less than people expect. Tokays can lighten or darken their skin, but in Phelsuma the 2013 study found limited evidence for rapid pigment movement inside cells, while pressure or dehydration shifted color by changing nanocrystal spacing in skin with the pigment removed.

So geckos mostly shift shade slowly, unlike the fast display of a chameleon. If skin turns dull, patchy or unusually dark and stays that way, have a reptile veterinarian look at it.

Juvenile, adult and sex differences

Sex differences are sourced for only a few geckos. Male tokays are brighter than females. Male African fat tailed geckos are marked by larger preanal pores and a bulbous tail base, not by color.

Crested gecko sexes look alike in color. Males show a hemipenal bulge at the tail base by 3 to 4 months of age.

Juvenile to adult color change is not documented for most species in an authoritative source. Hobbyists often report bands fading to spots in leopard geckos, but the sources used here did not confirm it. Treat juvenile color as a poor predictor of adult color.

Captive color lines

Captive breeding has produced looks that wild geckos do not show. Animal Diversity Web notes that many crested gecko variations are found only in captive bred animals. Its leopard gecko account lists trade forms such as high yellow, chocolate and albino, where albino lacks yellow and brown pigment.

Most named lines have never been tested by controlled crosses. Names such as granite, powder blue, calico or caramel are hobby names, with inheritance reported by breeders, not independently tested.

This page does not list them. The gecko morph index does, species by species.

For what recessive, dominant and incomplete dominant mean, read morph genetics.

One line has published data. The leopard gecko Lemon Frost, which appeared around 2015, has more white body color and brighter yellow and orange areas. A 2020 paper found malignant iridophore tumors in three affected geckos.

Breeders describe the trait as codominant, a report the authors relay rather than test. The authors recommended against breeding Lemon Frost until the cause is understood.

The tumors arose in iridophores, the reflective cells that normal leopard gecko skin lacks, which ties the extra white color to the disease. Color and health are linked in this line. Ask a breeder for the animal’s line and any health history before you buy.

Sex determination and color breeding

Breeding for color is easier when you know how a species inherits sex. African fat tailed and leopard geckos use temperature dependent sex determination, so incubation temperature sets the sex of the eggs. In the African fat tailed gecko, 24 to 28 C gives mostly females, 29 to 30.5 C roughly equal sexes and 31 to 32 C mostly males.

A color cross cannot predict sex ratio in these species.

For a quick check of a color cross, the gecko morph calculator is the place to start, with the caveats above.

How to judge a colorful gecko

A colorful gecko is not automatically a healthy one. Use these checks when you assess an animal.

• Compare the color with the species’ natural range in the table above. A bright animal may still be a normal wild type.
• Ask which line the animal belongs to, and whether it has documented health problems.
• Look for even skin, clear eyes and a full tail. Dull or patchy skin that does not clear after a shed needs a veterinary exam.
• Treat any claim about inheritance as a breeder report unless a paper backs it.

Read the morph overview for how color lines are named across reptiles.

Frequently Asked Questions

Why are some geckos blue or green?

The color is structural, made by ordered layers of guanine crystals in the skin. Yellow pigment above the crystals turns blue into green. This is documented in day geckos.

Are any geckos naturally striped?

Yes. About 10.3% of the 439 species in the pattern study were striped, and the African fat tailed gecko can have a white central stripe. Crested geckos include a tiger pattern.

Which gecko colors are wild and which are captive only?

Wild colors are documented in species accounts, such as the tokay’s red spots. Captive lines come from breeding and mostly lack tested genetics.

Do male and female geckos differ in color?

Only sometimes. Male tokays are brighter than females, while crested gecko sexes look alike. Many species show no sourced color difference at all.

Can a gecko’s color signal illness?

A lasting change to dull, patchy or unusually dark skin can point to stress, a bad shed or disease. Compare it with how the gecko looked before, and see a reptile veterinarian if it persists.

Is a bright captive line riskier to keep?

Not always, but one leopard gecko line has a documented link to tumors. Ask about the line and its health record before buying.