The aim of the present study was to assess the discoloration of the peri-implant mucosa caused by zirconia (Zr) and titanium (Ti) dental implants with and without soft tissue grafting (STG). Zr and Ti implants were inserted in edentulous areas in pig maxillae. Spectrophotometric measurements were performed prior to and after the insertion of the implants, and following the placement of a STG on the buccal side. A significant discoloration of the mucosa was observed with a mean ΔE of 8.05 (± 2.51) (Ti) and 4.93 (± 3.18) (Zr). In conjunction with a STG, ΔE values amounted to 5.31 ± 3.50 (Ti) and 5.95 (± 3.68) (Zr). The placement of Zr implants led to less discoloration of the mucosa than Ti implants without STG.