I note from the original screen grab you’re either using OS Dark mode (or dynamic mode switching). The suggested default scheme for OS Dark mode is ‘Dark Coral’, see here.
@eastgate may correct me here but the Tinderbox ‘color scheme’ system pre-dates OS dark/lite modes and so only stores one colour per setting. Thus a setting for $TextBackgroundColor intended for use in OS Light mode may not be ideal in OS Dark mode, and vic-versa. So, if you prefer to work in OS dark mode, ‘Modern’ may not be your ideal choice of scheme for new TBXs.