It is well known that keratinized mucosa (KM) plays a crucial role for maintaining peri implant health and esthetic outcomes. The Strip Gingival Graft (SGG) technique, which involved an apically positioned flap (APF), in combination with an autogenous SGG and a xenogeneic collagen matrix (XCM), demonstrated its efficacy in re-establishing an adequate amount of KM width at implant sites. Nevertheless, it is still unclear whether harvesting the SGG from the palate (pSGG) or from the buccal aspect of natural dentition (bSGG) affects the esthetic outcomes at the augmented implant sites. Therefore, the objective of the present study was to compare the esthetic outcomes of dental implants augmented with either bSGG + XCM or pSGG + XCM. The present study was designed as a single-center retrospective study, assessing the esthetic and colorimetric outcomes of peri-implant KM augmentation with either pSGG + XCM or bSGG + XCM in cohort of 49 subjects. The two groups were compared in terms of colorimetric outcomes, assessed on clinical photograph using specific software able to identify and quantify the predominant color within the peri implant soft tissue. Colorimetric comparisons with adjacent untreated sites were also investigated. In addition, the Pink Esthetic Score (PES) and the Subjective Esthetic Score (SEE) were performed to further assess the esthetic outcomes of pSGG + XCM and bSGG + XCM. The colorimetric analysis did not show statistically significant differences among sites augmented with pSGG + XCM, sites augmented with bSGG + XCM, and untreated sites. Implants treated with bSGG + XCM showed significantly greater PES (in terms of shape of the mesial and distal papilla, level of the soft tissue margin, soft tissue contour, anatomy of the alveolar process, and final PES) and SEE compared to implants augmented with pSGG + XCM. The present study demonstrated that implant sites augmented with APF with either pSGG + XCM or bSGG + XCM did not show different colorimetric outcomes compared to adjacent untreated sites, while bSGG + XCM obtained superior professional and subjective esthetic scores compared to pSGG + XCM.