If you hardcode the background to a fixed color, the 4-bit palette for foreground colors is generally to be avoided -- instead, use the 8-bit (256 color) or bigger palettes.
If I understand correctly, you're in the situation where you've chosen your 4-bit colors so that they render properly on an application which (incorrectly) uses an 8-bit background color but a 4-bit foreground color, and also that the colors don't render well on the default background that's part of the same 4-bit palette.
I think you'd be a great candidate for jj's ability to customize colors.
I don't choose anything; I just use the xterm defaults. Some colours inherently conflict. Blue on white is fine. Yellow on black is fine. Yellow on white is not. White on white is even worse. There are many combinations that don't really work brilliantly. Some applications set background colours, some don't. pamix, ngrok, and npm are examples of applications that hard-code background colours. Configuring the terminal to use text colours that work well with both the default white and hard-coded black (for some applications) is hard.
That I need to spend a bunch of time setting all of this up (among other things) is exactly how this thread started.
