In the late 19th century, progress in dye chemistry led to advances in industrial organic chemistry in Germany. Over the next few decades, this revealed dyes not just as color agents but as promising lead compounds for drug development. Collaborations between dye chemists and medical researchers were crucial in turning these unexpected discoveries into structured medicinal chemistry efforts. The outcomes included major drug classes like sulfa antibiotics, antifungal azoles, and others, resulting in a legacy where dyes served not only as biological stains but as crucial tools for understanding complex natural products and drug interactions. Today, the impact of dye molecules persists in clinical therapies, molecular probing, pharmacokinetic tracing, and high‐throughput screening. This review underscores the historical contributions shaping contemporary pharmaceutical sciences, highlighting the role of dyes as indispensable tools propelling drug discovery across generations.