Chromatophores are largely responsible for generating skin and eye colour in poikilothermic animals and are generated in the neural crest during embryonic development. Mature chromatophores are grouped into subclasses based on their colour under white light:

xanthophores (yellow): contain yellow pigments in the forms of carotenoids
erythrophores (red): contain reddish pigments such as carotenoids and pteridine
melanophores (black/brown): contain black and brown pigments such as the melanins
cyanophores (blue): limited taxonomic range but found in some fish and amphibians

Structural colours
Animals can also appear coloured due to structural colour, the result of coherent scattering perceived as iridescence. The structures themselves are colourless. Light typically passes through multiple layers and is reflected more than once. The multiple reflections compound one another and intensify the colours. Structural colour differs according to the observers position whereas pigments appear the same regardless of the angle-of-view. Animals that show iridescence include mother of pearl seashells, fish, and peacocks. These are just a few examples of animals with this quality, but it is most pronounced in the butterfly family. iridophores (reflective/iridescent): sometimes called "guanophores", reflect light using plates of crystalline chemochromes made from guanine
leucophores (reflective white): found in some fish, utilize crystalline purines (often guanine) to produce a reflective, shiny, white colour. Plant colouration
The primary function of pigments in plants is photosynthesis, which uses the green pigment chlorophyll along with several red and yellow pigments including porphyrins, carotenoids, anthocyanins and betalains. Definition
Definitions of albinism vary and are inconsistent.
Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and pink or blue eyes. Individuals with the condition are referred to as albino. Varied use and interpretation of the terms mean that written reports of albinistic animals can be difficult to verify. Albinism can reduce the survivability of an animal; for example, it has been suggested that albino alligators have an average survival span of only 24 hours due to the lack of protection from UV radiation and their lack of camouflage to avoid predators. It is a common misconception that all albino animals have characteristic pink or red eyes (resulting from the lack of pigment in the iris allowing the blood vessels of the retina to be visible), however this is not the case for some forms of albinism. Familiar albino animals include in-bred strains of laboratory animals (rats, mice and rabbits), but populations of naturally occurring albino animals exist in the wild, e.g. Mexican cave tetra. Albinism is a well-recognized phenomenon in molluscs, both in the shell and in the soft parts. It has been claimed by some, e.g. that albinism can occur for a number of reasons aside from inheritance, including genetic mutations, diet, living conditions, age, disease, or injury. However, this is contrary to definitions where the condition is inherited. Oculocutaneous albinism (OCA) is a clearly defined set of seven types of genetic mutations which reduce or completely prevent the synthesis of eumelanin or pheomelanin, resulting in reduced pigmentation.