When a walnut does not develop the colour you expected

This is an English reading overview of the Chinese article, rather than a complete translation. The Chinese source has been updated since this overview was prepared; consult the original for the latest details.

The central idea

Colour development depends on the shell, surface, natural handling potential and any interventions, as well as the care routine. Do not assume every disappointing change is the collector’s fault. Reassess the foundation and avoid forcing a result with oil or polishing simply to meet a colour deadline. Colour is one result of a longer process. A better question is whether the walnut has a sound, natural foundation for stable handling and surface development. Check risks, shell quality and surface condition, and avoid forcing red colour as if it were the only measure of success.