The Phase 1 Renault 5 GT Turbo was available in the following paint colours / codes as outlined below. Note, not all of the cars in the attached images are Phase 1 cars, and are for colour example purposes only.
Unlike the Phase 2 cars, the Phase 1 cars chassis plate may not list the paint code unless it is a very late phase 1 car, with the oval symbol embossed in the plate. Instead, the paint code is shown on a large sticker on top of the RHS suspension strut tower as shown in one of the attached images.