Microplastic pollution resulting from the degradation and  wear of polymer materials has become one of the major  environmental concerns associated with the widespread use  of plastics. In this study, thermoplastic polymers based on  acrylonitrile-butadiene-styrene (ABS), polylactic acid (PLA),  and polycarbonate (PC) were modified with carbon-based  additives, namely DTX (selectively ion-modified activated  carbon) used as a functional carbon filler and wood-derived  activated carbon, and evaluated under accelerated aging  conditions. The aim of the work was to determine how these  modifiers affect the aging behavior, color stability, and surface  condition of the investigated materials. The specimens were  prepared by injection molding and then exposed to accelerated aging in a Xenotest climatic chamber under Arizona test  conditions. Optical stability was monitored by color measurements expressed as L*, a*, b*, and total color difference  ΔEab, while surface-related changes were examined by scanning electron microscopy (SEM). The results showed that  the modified formulations exhibited lower ΔEab values than  the corresponding reference materials, indicating improved  color stability during aging. SEM observations confirmed  that accelerated aging induced degradation-related features,  including microcracks, local peeling, delamination, and surface irregularities, although the extent and character of these  changes depended on both the polymer matrix and the type  of modifier used. The results indicate that carbon-based modification can improve the aging resistance of thermoplastic  polymers, particularly in terms of optical stability, while also  influencing the development of surface degradation during  exposure. These findings suggest that the effectiveness of  the modifiers is strongly formulation-dependent.