This issue has persisted since Forza Motorsport 4. The RX-8 R3 in FM is a USDM model, meaning it had two factory colours available, those being Velocity Red and Aurora Blue. Other markets got different colours, with Canada recieving Crystal White Pearl instead of Blue, and Japan and Europe getting Crystal White Pearl and Diamond Gray.
Considering that Forza isn’t exactly known for full car accuracy, all 4 colours could be included for the RX-8 R3 in the game.
Aurora Blue:
Crystal White Pearl (Canada):
Diamond Gray:
