Merge the two colorschemes into a single file and a single colorscheme with two different appearance, one for each background, and don't force change the background. I would suggest something like "yinyang.vim" or "yin-yang.vim". In the current environment most dual (dark and light) colorschemes ship as one file. Such a single file wouldn't change the background color. As it currently is, both of the separate yin and yang force-change the background color. The current split files also break color switchers and so on, because the two files jump back and forth in the list between each other, in addition to changing the background, which makes it difficult to do all-light or all-dark comparison passes in the switcher. Because of the force-change to background color, they also break whatever built-in dark/light mode settings you might be using. I like the yin and yang schemes but the separate is making me consider uninstalling them and they would benefit from being modernized.

Background changes are forced here: