Calico or nacreous goldfish are goldfish of any breed that have a type of scale that is intermediate between the metallic type of scales and the transparent type. These scales have a slight sheen that produces a pearly appearance. The name "calico goldfish" came about because the first fish that were introduced with this type of scales had a mottled calico pattern with several colours. Calico goldfish often have patches of red, yellow, grey and black along with dark speckles on a blue background. This coloration usually extends over the fins.