Core Viewpoint - Apple is actively investigating reports of color changes in the iPhone 17 Pro and iPhone 17 Pro Max, indicating that the issue is likely a limited manufacturing defect rather than a widespread problem [1][8]. Group 1: Investigation and Response - Apple has begun recalling affected iPhone 17 Pro and iPhone 17 Pro Max units to assess the root cause of the color change [1]. - Users can be assured that the likelihood of encountering color change issues is very low, and Apple will provide after-sales support if such problems arise [1]. Group 2: Manufacturing Process - The iPhone 17 Pro's body material has shifted from titanium to aluminum to reduce weight and improve heat dissipation [1]. - Traditional painting methods are ineffective for aluminum, leading Apple to use a complex "anodizing" process to achieve durable coloring [3]. Group 3: Anodizing Process Details - The anodizing process involves cleaning and etching the aluminum surface, followed by immersing it in an electrolyte solution to form a porous aluminum oxide layer [3]. - After forming the porous layer, orange dye is injected into the micro-pores, and the critical final step is "sealing" to lock the dye in and enhance corrosion resistance [6]. Group 4: Root Cause of Color Change - Improper sealing during the anodizing process can leave the porous surface open, leading to color changes due to absorption of moisture, oils, and sunlight [8][10]. - The uniformity of the color change observed in the affected devices suggests a failure in the sealing process rather than user cleaning issues [12].