My AS hatch grain lost color simply by polishing them. I always condition and then polish a new pair of shoes. When I did so, the medium brown coloration simply came off. All my attempts to darken the effected areas failed. Color simply would not take.
I had a similar issue with an Alfred Sargent chukka boot. My understanding was that it was an issue with the hatch grain calf, sourced from Horween, that seemed to have trouble holding the color.
For this to happen on such a high end shoe as St. C. is unacceptable.