In Neopia, pets have different colours. They come in the standard, basic colors: red, yellow, green and blue. Because it is one of the basics, all pet species can be blue. A pet can be changed to blue with a magical paint brush, the Lab Ray, a Fountain Faerie quest, or, for some species, a morphing potion or magical plushie . Often times users will receive a starter blue paint brush. This non-tradeable item can be used to paint your pet, and is only for one time use. Your pet will then be blue.
You can see an example of a blue neopet below.