The idea here is that what ever color stone you choose to be inverted will play on the center stone, slightly changing the color and the amount of visible facets. This will increase the color tones and the visible fire to whatever stone you choose to be in the center as well as boosting the overall beauty! I would suggest that you use a diamond in the center so that it will pick the color and extra facets from the bottom inverted stone. Give me feedback and let me know if you like this design!