Hydrorybina violascens is a moth in the Crambidae family. It was described by Hampson in 1917. It is found on Borneo. The wingspan is about 16 mm. The forewings are cupreous red-brown with a purplish gloss. There is an oblique dark brown antemedial line and a dark discoidal bar. The postmedial line is black-brown and the termen is black-brown with a silvery gloss. The hindwings are cupreous red-brown with a purplish gloss. The costal area is whitish with some dark irroration below the end of the cell, as well as a black postmedial line.