Codex Terminal renders explicit black-on-white ANSI text as blank white blocks

What version of the Codex App are you using (From “About Codex” dialog)?

Version 26.616.71553 • Released Jun 22, 2026

What issue are you seeing?

Codex Desktop's built-in terminal renders explicit black-on-white ANSI text as blank white blocks.

This affects ordinary SGR foreground/background styling. Inverse video renders correctly, so this looks specific to explicit foreground/background color handling rather than all inverted or high-contrast cells.

What steps can reproduce the bug?

Run this in the Codex Desktop app terminal:

printf '\033[30;47mBLACK ON WHITE\033[0m\n'
printf '\033[7mINVERSE VIDEO\033[27m\n'

What is the expected behavior?

The BLACK ON WHITE text should be visible as black text on a white background, matching normal ANSI terminal behavior.

The inverse-video line should also remain visible.

What do you see instead?

The explicit black-on-white span renders as a blank white rectangle, so the text is not readable.

The inverse-video line renders correctly.

Additional information

This is related in area but distinct from #27126, which reports block cursor readability. This repro does not depend on cursor shape; it uses ordinary ANSI SGR text styling.

Screenshot to be attached in a follow-up comment.