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

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 OC-13047, OC-11441, and OC-12486 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

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.

same issue with ghostty on Arch Linux version on opencode 1.14.19

Interesting, until 1.14.19 I used to had correct theme rendering in macos in Ghostty.

I noticed solarized light becoming dark in wezterm. My theme is light and opencode was also light. After todays update, opencode turned dark with same setting.

It looks like #23188 this PR might be related to how theme become inverted in 1.14.19 release

@kommander

@kommander, could you please check if my suggestion is correct? In iTerm opencode renders in correct theme, so maybe it's only Ghostty issue

@wKich

@wKich I’m using wezterm and seeing the same (on macos)

same here (ghostty + ubuntu). Worked fine in 1.14.18

Can you try ctrl+p and then "Unlock theme mode"?

@kommander

I'm having the same issue on ghostty + macOS regardless if I'm using tmux or not. Commented in #20926.

@kommander If it helps, I attempted ctrl+p and then "unlock theme mode" with no visible changes. Attempted to restart opencode and then also tried restarting ghostly as well with no change after toggling that option. Behavior is still present. This seems to have only started occurring in the 1.14.19 release. 1.14.18 and lower work fine when this was fixed a few weeks ago originally.

Mine is

opencode --version
1.14.18

and I am experiencing this issue, [un]lock theme mode doesn’t do anything.

Adding another reproducible macOS + Ghostty report.

On this machine:

OpenCode 1.14.20
Ghostty on macOS with theme = light:Catppuccin Latte,dark:Catppuccin Mocha and window-theme = auto
OpenCode TUI config set to theme: "github" in ~/.config/opencode/tui.json

I removed all persisted mode overrides from ~/.local/state/opencode/kv.json, so it now only contains theme: "github":

no theme_mode_lock
no theme_mode

Unlock theme mode had no effect.

Behavior I am still seeing:

Set macOS to dark mode
Ghostty switches to dark correctly
Fully quit OpenCode
Reopen OpenCode
OpenCode still renders the light variant

I also tested theme: "system" and it still did not follow correctly, so this does not look specific to the github theme itself.

This seems consistent with the CSI 996 / OSC 11 mismatch discussed above: startup mode detection still appears wrong even after removing the lock/cache state.

Adding a stronger repro/data point here. This is not just a stale lock/cache issue on my machine.

Environment:

OpenCode 1.14.20
macOS
Ghostty
theme = light:Catppuccin Latte,dark:Catppuccin Mocha
window-theme = auto
OpenCode TUI theme set to github
tested in a plain native Ghostty tab, not inside tmux

My persisted OpenCode state is clean:

~/.config/opencode/tui.json contains only theme: "github"
~/.local/state/opencode/kv.json contains only theme: "github"
no theme_mode_lock
no theme_mode

I ran the maintainer probe script directly in the same Ghostty tab where I launch opencode.

In macOS light mode, Ghostty reports light correctly:

theme queries:
  CSI ?996n      light
  OSC 10 (fg)    #4c4f69   rgb( 76,  79, 105)
  OSC 11 (bg)    #eff1f5   rgb(239, 241, 245)

In macOS dark mode, Ghostty reports dark correctly:

theme queries:
  CSI ?996n      dark
  OSC 10 (fg)    #cdd6f4   rgb(205, 214, 244)
  OSC 11 (bg)    #1e1e2e   rgb( 30,  30,  46)

So Ghostty itself is returning the expected mode/colors.

But OpenCode is still wrong:

in macOS light mode, OpenCode command palette shows Lock theme mode and Switch to light mode
after switching macOS to dark mode, OpenCode still shows Lock theme mode and Switch to light mode

That means OpenCode believes its current mode is already dark in both cases, even though the terminal probe in the same tab reports light and dark correctly.

So on this machine the issue seems narrower than "Ghostty reports the wrong theme":

terminal probe outside OpenCode is correct
no persisted theme lock/cache is present
OpenCode 1.14.20 still starts/behaves as if mode is stuck on dark

Seems like related to this code block i guess:

function mode(background: RGBA | null): "dark" | "light" {
  if (!background) return "dark"
  const luminance = (0.299 * background.r + 0.587 * background.g + 0.114 * background.b) / 255
  return luminance > 0.5 ? "light" : "dark"
}

Fixed in v1.14.20

"Fixed a system theme regression in the TUI."

Tested on 2 macs, works normally now.

@jepachecoam

@jepachecoam consider closing

@coygeek

@coygeek

I'm seeing it always detect dark mode now instead (as in, even when the terminal is light). Happy to provide input.

I guess this specific issue could be closed, but it seems like the root problem is ongoing?

I see this in dark mode (aka macos dark mode) which matches my opencode dark mode:

I see this in light mode (aka macos light mode) which matches my opencode light mode:

tui.json:

{
  "$schema": "https://opencode.ai/tui.json",
  "theme": "vercel"
}

Looks normal to me. Using Ghostty, not terminal.

@pearofducks

@pearofducks

Quick fix:

Clone the repository
Fix packages/opencode/src/cli/cmd/tui/util/terminal.ts line 22
from:

function mode(background: RGBA | null): "dark" | "light" {
  if (!background) return "dark"
  const luminance = (0.299 * background.r + 0.587 * background.g + 0.114 * background.b) / 255
  return luminance > 0.5 ? "light" : "dark"
}

to:

function mode(background: RGBA | null): "dark" | "light" {
  if (!background) return "dark"
  const luminance = 0.299 * background.r + 0.587 * background.g + 0.114 * background.b
  return luminance > 0.5 ? "light" : "dark"
}

run OPENCODE_VERSION=1.14.20 npx -y bun@1.3.11 run --cwd packages/opencode build --single to build.
copy build binary using cp $HOME/path/to/opencode/packages/opencode/dist/opencode-linux-x64/bin/opencode" "$HOME/.opencode/bin/opencode"
run opencode as usual

Tested on Ubuntu 24.04, hyprland WM, terminal emulator: kitty and warp terminal.

@coygeek

@coygeek - I'm not using the dynamic switcher and am rather modifying my config file to point to a light or dark theme. Like I said I'm happy to provide more info to help you reproduce the issue!

I can confirm @Klassikcat's suggested fix works on light and dark mode.

(I had to build using 1.3.13 of Bun instead)

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Themes always render light variant on macOS regardless of terminal dark background (OSC 11 detection broken) #23196

Description

Plugins

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Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

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Themes always render light variant on macOS regardless of terminal dark background (OSC 11 detection broken) #23196

Description

Description

Plugins

OpenCode version

Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

Activity

github-actions commented on Apr 17, 2026

victoralensai commented on Apr 20, 2026

wKich commented on Apr 20, 2026

klement commented on Apr 20, 2026

wKich commented on Apr 20, 2026

wKich commented on Apr 20, 2026

klement commented on Apr 20, 2026

joaomj commented on Apr 20, 2026

kommander commented on Apr 20, 2026

WolffTech commented on Apr 20, 2026

klement commented on Apr 20, 2026

5 remaining items

coygeek commented on Apr 22, 2026

coygeek commented on Apr 22, 2026

Klassikcat commented on Apr 23, 2026

coygeek commented on Apr 23, 2026

coygeek commented on Apr 23, 2026

pearofducks commented on Apr 23, 2026

coygeek commented on Apr 23, 2026

Klassikcat commented on Apr 23, 2026

pearofducks commented on Apr 23, 2026

github-actions commented on Jul 3, 2026

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