I noticed this was noted in the S9 forums but, this case applies to S10's. Themes not available in the ease of Dark Mode. Constant bright light is stressful on my eyes as I do not like the default appearance. Now with S10s/S20s and Android 10, why is there still a restriction on the use of themes and Dark Mode? The below screenshots show before and after Dark Mode in settings.
Themes in Light Mode.
Themes in Dark Mode.
I've provided additional examples in the replies.