In French, the two kinds of pollack, the go-to fish in fish fingers, are distinguished. There’s lieu jaune (Pollachius pollachius) and lieu noir (Pollachius virens), the one with a grey tint to the flesh, also known as coley or coalfish.
Colin is a commercial name for frozen pollack. Other names for it are colin noir, colinet or even colineau for a little one.
Image by Citron / CC-BY-SA-3.0