If you have to preface an idea about its potential confusing nature, that should be a warning that it might not best serve your users.
In my opinion, the existing UI widget that solves this problem best is a plain old group of radio buttons (auto, light, dark). Two checkboxes that interact with each other and also a sometimes-hidden label is something new for users to learn and also more complex to implement and maintain.
In my opinion, the existing UI widget that solves this problem best is a plain old group of radio buttons (auto, light, dark). Two checkboxes that interact with each other and also a sometimes-hidden label is something new for users to learn and also more complex to implement and maintain.