The assignment of curves to specific clusters is reconstructed into an image in Fig. and overlaid with the locations of the first pits that appear immediately after passive film formation. The magnified images in Fig. reveal that pits predominantly emerge in pixels assigned to the blue cluster, which corresponds to areas with lower average normalized intensities. For example, Pits 1 and 2 are surrounded by blue-clustered pixels, while Pits 4, 6, and 7 are located directly within blue-clustered areas. Although Pits 3 and 5 are not directly within blue-clustered pixels, they are surrounded by them. This observation, along with a more detailed analysis provided in the SI for all pits, indicates that pits always appear in the direct proximity of blue-clustered pixels and never within the white-clustered areas in Fig. (also depcicted as orange in Fig: ), which are associated with higher average normalized intensities.