Flower pigmentation is a critical trait in plants, influencing ecological interactions and ornamental value. This study investigates the mechanisms underlying petal coloration in Prunus campanulata and its hybrids, Prunus ‘Okame’ and Prunus ‘Yoko’. Morphological analysis revealed consistent flower size across varieties, indicating that color variation is not linked to structural differences. Physiological and biochemical analyses identified stages III and IV as critical for pigmentation, characterized by the significant accumulation of flav...