Color purity in analog is based on chemistry. Color negative films are the best capture medium and color prints from them by any means (including scans and digital prints). Digital systems capture color reasonably well and have software to fix any problems. The real problem comes in grain and sharpness. Digital fails.

As far as image stability, analog films last for years while digital storage is rather fugitive. Analog prints are quite stable, and the prediction now is for Endura and CA prints to last for up to 200 years depending on storage. Digital prints are an unknown quantity at this time due to a number of issues. So, one cannot say.