Automatic light / dark theme switching is not fully working

[andreynering]

Issue Description

This is a quite annoying bug that has been happening on Ghostty for quite some time. On #9743 it is said it was supposedly fixed recently, but for me that bug is still happening.

I have this in my config:

theme = dark:Dracula,light:Alucard

I use Ghostty on macOS and I use Nightfall to be able to quickly switch between light and dark themes with a single click.

Most of the time it works as expected, but at a random way some specific panels don't switch. When it happens, switching back-and-forth a second time between light and dark themes don't usually work. You really have to close that panel or tab and open a new one.

Expected Behavior

Themes should switch as expected:

Actual Behavior

Some panels or tabs don't really switch:

Reproduction Steps

While writting this discussion and trying to reproduce it, I discovered that I can reproduce it by opening and closing a TUI app on that panel. Once you do that, the theme won't switch automatically from that point forward.

This probably means the bug is related to the fact some TUIs set a custom background color while running.

Ghostty Logs

No response

Ghostty Version

Ghostty 1.3.0

Version
  - version: 1.3.0
  - channel: stable
Build Config
  - Zig version   : 0.15.2
  - build mode    : .ReleaseFast
  - app runtime   : .none
  - font engine   : .coretext
  - renderer      : renderer.generic.Renderer(renderer.Metal)
  - libxev        : kqueue

OS Version Information

macOS Tahoe 26.2

(Linux only) Display Server

None

(Linux only) Desktop Environment/Window Manager

No response

Minimal Ghostty Configuration

theme = dark:Dracula,light:Alucard

My Ghostty config is here: https://github.com/andreynering/ghostty

### Additional Relevant Configuration

_No response_

### I acknowledge that:

- [X] I have reviewed the FAQ and confirm that my issue is NOT among them.
- [X] I have searched the Ghostty repository (both open and closed Discussions and Issues) and confirm this is not a duplicate of an existing issue or discussion.
- [X] I have checked the "Preview" tab on all text fields to ensure that everything looks right, and have wrapped all configuration and code in code blocks with a group of three backticks (` ``` `) on separate lines.

[max-farver]

I am having the same issue on Linux running KDE Plasma. Any tab with Neovim open when the theme changes is stuck with the background of the previous theme.

[kikidotdirectory]

i am also having this issue, except it seems to occur when i have a neovim tab open and the theme switches while the computer is asleep

2026-04-03.at.12.44.57.mp4

[pickx]

I think it's something about programs using the alternate screen. I commonly see it with: helix, claude, ptpython. I also suspect wakeup from sleep is related, but maybe it's not required.

I have seen this bug since the start of 2026 at least, typically every day where I'm using a program such as one of the above.

@bo2themax I apologize for pinging, but I believe this bug needs more attention.