In today's digital landscape, understanding generational color preferences has become crucial for marketing success, particularly as Gen Z emerges as a dominant consumer force alongside Millennials. While previous research has extensively documented Millennial color preferences in marketing, Gen Z's distinct aesthetic sensibilities – characterized by their preference for muted pastels and '90s-inspired palettes – suggest a significant shift in color psychology across generations. This study investigates how color preferences in social media advertising differ between Gen Z (born 1997-2012) and Millennials (born 1981-1996), with particular attention to engagement rates, purchase intent, and brand perception. Through a systematic review of recent marketing campaigns, consumer behavior studies, and social media analytics, this research examines the evolution of color trends and their effectiveness across platforms like TikTok, Instagram, and YouTube. The findings aim to provide marketers and designers with actionable insights for creating generation-specific color strategies that enhance campaign performance and brand resonance. Understanding these generational color preference shifts will help brands better target their visual marketing efforts and adapt to evolving consumer aesthetics in the social media age.