Little off topic I know, but I went to an airfield in England that has an original Spitfire prototype on display. When they did the restoration they wanted to match the original light blue colour.
They managed to track down a model plane that the designer, RJ Mitchell had built for his son as a toy, painted with the original prototypes paint. They then took a tiny chip of paint from the model and had it colour-matched and used that on the full size version.
Nice....