For example, I have marked around the areas I’m talking about with red in the image.
It appears that you are asking to change the ui.font.color of the menuBar and menuItems. Wouldn’t that depend on the operating system? e.g., on a Mac the font color changes when the Appearance changes. Dark mode uses a light colored font while Light mode uses a darker colored font. There are several colors in the theme.txt file in the main Processing sketchbook folder; you can check there, but I didn’t find anything to change the menuBar font color.
I tested every option in theme.txt, but to no avail.
What operating system, ie macOS, windows, or linux?
I’m using Windows. Thanks.