Metroid Prime 3: Corruption/Credits

Red Credits
You can get Red Credits by scanning creatures.

Blue Credits
You can get three Blue Credits by saving GF Troopers on the G.F.S. Olympus at the start of the game. The rest are obtained by collecting Lore scans.

Gold Credits
Gold Credits can be obtained by defeating bosses and achieving certain goals. Some bosses have a separate credit for defeating them on Hypermode difficulty.