A pale purple color, often used to describe flowers, fabrics, or decorative items. 'Orchid' is a common English equivalent in color contexts.
She was wearing a light purple dress.
This flower is light purple and very beautiful.
Compound of 薄 (usu, 'light, pale') + 紫 (murasaki, 'purple') + 色 (iro, 'color'). The reading うすむらさきいろ is a straightforward combination of the readings of its components.