1 - Why do those messages show up?
They happen because your app was built on Debian where ncurses uses symbol versioning, but Fedora’s ncurses doesn’t match that. The loader complains, but the functions are still there so it runs fine.

2-A - Why are some combination of colors different?
That’s down to terminal settings and terminfo differences. Things like $TERM, bold-as-bright behavior, or different default palettes can make colors look off between distros.

2-B - Is there a way to adjust it?
Try rebuilding on Fedora to kill the warnings. For colors, set the same $TERM everywhere, copy the terminfo from the system you like, and avoid tricks like bold-for-bright if you want consistent colors.