How can two igneous rocks have everything in common but not color?

Two igneous rocks can share similar mineral compositions, textures, and formation processes, yet differ in color due to variations in mineral abundances or types. For example, a rock may contain a higher percentage of dark-colored minerals like biotite or amphibole, while another may have more light-colored minerals like quartz or feldspar. Additionally, factors such as cooling rates and environmental conditions during formation can influence the crystal structure and overall appearance, leading to differences in color despite their commonalities.