Tui colors are hard to read in light mode

I love ghcup tui, however, in my default terminal (black text on white background, aka "light mode"), two important colors are unreadable:

• Whatever is highlighted is given a background color that is dark blue. The black text is unreadable against this background.
• Every release marked with latest is given a foreground color that is either white or some very light color. It is invisible against the white background.

To reproduce this issue, try something on the order of

xterm -fg black -bg white

and then run

ghcup tui

in the resulting terminal.