What does Cynthia mean?
Cynthia is from Greek Kynthia, an epithet of Artemis meaning 'from Mount Cynthus,' her birthplace on Delos. The moon association comes because Artemis (and Selene) were called Cynthia; it is cultural, not a literal 'moon' etymology.
What does Chloe mean?
From Greek 'chloe' (Χλόη) meaning 'green shoot, young growth of a plant'. It was an epithet of the harvest goddess Demeter marking the fresh green of spring.