I see a momentary flash of the opposing color scheme on refresh or when I open a link in a new tab. I also see a similar flash after posting a new reply for some reason.
I have a light theme enabled, and my OS is set to dark mode. So I see the difference when I’m toggled back to light.
I guess the colors are switched on the client side, but it looks like user settings are left untouched? Is it possible to maybe update the user “color scheme” preference on toggle to avoid this? The client-side switch can provide the seamless transition, and changing the user preference can avoid the brief flash of the opposing color scheme on refresh?