Plate mail changing colors

I colorized my platemail one or two releases ago into dark blue (as black was not available).

In this release the color changed automatically to black but it is no longer noted that it is colorized.
In addition each time I visit Valhold (and only this!) my plate mail changes colors again. This time to pure metallic. When I leave Valhold it changes back to black.

I have not yet tried to recolorize the armor by hand.