What does Viola mean?
Viola is the Italian and Latin word for the violet flower.
What does Bella mean?
Directly the Italian/Spanish word bella 'beautiful', from Latin bella/bellus. NOTE: as a given name Bella is most often a short form of Isabella, whose own meaning is 'pledged/devoted to God' (a Hebrew-origin name, NOT beauty); Bella qualifies here only on the strength of the standalone Italian word 'beautiful'.