Hi:
Unfortunately as long as the root canal tooth is there, any fix will be temporary. Ultimately, a zirconium implant with a zirconium abutment may be the only way to get rid of the gray.
Best,
Dr. Maddahi
Hi
Given 6 years has passed, there will most likely be some gum recession. The gum in this region is very thin and when exposed the underlying non-vital tooth structure can appear prominent in color even if it is only a millimeter. If there is no pathology there may be options...