Themes always render light variant on macOS regardless of terminal dark background (OSC 11 detection broken)

[jepachecoam]

Description

Since April 17, 2026, OpenCode renders the light variant of all themes
regardless of the terminal's actual background color. The dark variant
never loads. This happens across multiple terminals on macOS.

This appears to be related to #21870, #19254, and #20926 but with a
broader scope — it is not limited to one terminal or theme.

Plugins

engram, "plugin": ["@mohak34/opencode-notifier@latest"],

OpenCode version

1.4.10

Steps to reproduce

open opencode.

Screenshot and/or share link

Operating System

mac

Terminal

Ghostty

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Theme detection fails to use dark variant despite OSC 11 returning dark background color #21870: Theme detection fails to use dark variant despite OSC 11 returning dark background color (same root cause: OSC 11 detection, dark variant not rendering)
• no longer respects system theme (macos ghostty) #20926: no longer respects system theme (macOS Ghostty) — same OS and terminal, same symptom

If your issue is distinct from these, please add details explaining what differs. Otherwise, consider adding a +1 or additional context to one of the existing issues.