Geckos come in various colors and patterns. Some are subtly patterned, and somewhat rubbery looking, while others can be brightly colored . Some species can change color to blend in with their surroundings or with temperature differences. Some species are parthenogenic, the females capable of reproducing without copulating with a male. This improves the gecko's ability to spread to new islands.
The toes of the gecko have attracted a lot of attention, as they adhere to a wide variety of surfaces, without the use of liquids or surface tension. Recent studies of the spatula tipped setae on gecko footpads demonstrate that the attractive forces that hold geckos to surfaces are van der Waals interactions between the finely divided setae (almost 500,000 setae on each foot, and each of these tipped with between 100 and 1,000 spatulae) and the surfaces themselves. The length of each seta is twice the diameter of a human hair, i.e 100 millionth of meter and each spatulae is 200 billionth of meter long just below wavelength of visible light. These kinds of interactions involve no fluids; in theory, a boot made of synthetic setae would adhere as easily to the surface of the International Space Station as it would to a living room wall, although adhesion varies with humidity and is dramatically reduced under water, suggesting a contribution from capillarity. The setae on the feet of geckos are also self cleaning and will usually remove any clogging dirt within a few steps.