Is there any way to fix it so that pages with night mode enabled don't have invisible text. A lot of charts have white text on white background when night mode is on.
Switched to night mode and see what you mean. Those tables have been hard-coded to those background colours instead of using a table class (default is class=ffxi-table in the header, though there are other styles). All we can do is fix them manually as we come across them by adding the class and deleting the colour overrides.