There is a perception (especially in the West) that yin and yang correspond to evil and good. However, Taoist philosophy generally discounts good/bad distinctions and other dichotomous moral judgments, in preference to the idea of balance. Confucianism (most notably the philosophy of Dong Zhongshu, c. the 2nd century BCE) did attach a moral dimension to the idea of yin and yang, but the modern sense of the term largely stems from Buddhist adaptations of Taoist philosophy.
This seems like a perfect name for our new kitty. Introducing.... Miss Yin Yang McKendree!!!!