@anselmschueler The only thing changing here is colors. For the light and dark style, app developers are expected to support those. The colors are the stable and can be relied on by developers. The accent colors are only used in specific spots and care is put into ensuring changing accent colors does not break apps.
The padding, borders, text style, and more are not changing when you change between light or dark styles or change accent colors. Those things can change drastically when you introduce full CSS theming.
@brainblasted I see. I would still call it theming though.