Dental Implant crowns are showing grey through tooth and grey line at gum? (Photo)

Congenitally missing lateral incisors had Invisalign starting at 11 (more aesthetic than traditional braces). At 17 my prosthedontist placed Marilyn bridges until I could get implants (still growing). I got implants last year, titanium. Then the prosthedontist set the ceramic/porcelain crowns on custom abutments, with screws. My gums seemed concave so periodontist did gum graft which slightly helped. Now I see grey in the actual crown in sunlight. I also see a slight grey line at gum and crown.