An Italian shoe shine master in Rome works on my old shoes. From gray color they became almost new. Great technic and good products like beeswax on this video, easy to find on Amazon: https://amzn.to/37ZIHq2
From same brand Saphir but best quality of beeswax: https://amzn.to/2R6Gti6
Saphir Natural Horsehair Shoe Brush: https://amzn.to/2Reei0O
Enjoy the video and relax