I did some further testing.
Starting position: Dark theme but all tables had formatting in "light mode" - shouldnt have.
Hiding header tables didn't work
Then I switched theme to light, did full deploy.
Result: all tables kept the same formatting (what was OK for light theme).
Again, hiding header did not work.
Then I switched theme to dark again, did full deploy.
Result: all tables kept the same formatting - what is not OK for dark theme.
Again, hiding header did not work
Then in dark mode I did reset the base color to that green blue color and did full deploy.
Result: all tables changed formatting according to dark mode and I am also able to hide the header for selected tables.
Do you do some "hidden" calculation using the base color and depending on that calculation you give recommendation for the color of side bar (dark or light) and also for the table formatting (dark style, light style)?