Is there any way to lighten the color of metal posts before situating a new crown?

I have a pair of dental implants in which the underlying metal posts are dark grey. My dentists indicated that zirconia crowns would ensure that the posts did not show through. I had the final procedure done last week and, unfortunately, they do. Is there any way to lighten the color of the posts before situating the new crown to negate this discoloration from showing through? If not, is there a crown material that will effectively mask a dark grey/black metal post?