patrick_y[PuristSPro Moderator]
33533
Good question. A potential alternative would be to ask Patek Philippe to make your custom colored straps...
Assuming that you're after custom colors, Patek Philippe has a very wide range of straps in their strap catalogue. But if you're after materials that isn't offered in their catalogue, then you're out of luck. Personally, I would avoid using steel spring bars on a watch that came with gold spring bars as there is a small chance that there would be some eventual excessive wear.