## Summary

Qt 6.12.0 ships a new built-in `QtQuick/Color` singleton, which shadows Omarchy's `qs.Commons.Color` singleton. Every `Color.<surface>.<role>` expression in the shell now evaluates to `undefined`, so the bar, `SUPER + SPACE` menu, OSD, lock screen, polkit agent and all panels render blank or black.

This is not a quickshell or ABI problem, and not stale caches: it reproduces in plain Qt 6.12 QML with no quickshell involved.

## Environment

- Omarchy `4.0.4-1` (`/usr/share/omarchy/shell/Commons/Color.qml` owned by the `omarchy` package)
- **`qt6-base` `6.12.0-2`**, `qt6-declarative` `6.12.0-1` (extra), upgraded 2026-10-08 13:25
- `quickshell` `0.3.1-1`
- Hyprland session, Wayland

## Steps to reproduce

1. Have Qt 6.12 installed with an `omarchy` build that exports `qs.Commons.Color` (any release through `4.0.4`).
2. `omarchy restart shell`
3. Open `SUPER + SPACE`, or just look at the bar.

The shell's journal fills with:

```
WARN scene: @plugins/bar/Bar.qml[81:-1]: TypeError: Cannot read property 'active' of undefined
WARN scene: @plugins/bar/Bar.qml[75:3]: Unable to assign [undefined] to QColor
WARN scene: @Ui/PanelToolTip.qml[21:-1]: TypeError: Cannot read property 'text' of undefined
WARN scene: @Ui/PanelToolTip.qml[22:-1]: TypeError: Cannot read property 'background' of undefined
WARN scene: file:///usr/share/omarchy/shell/plugins/lock/LockView.qml[127:-1]: TypeError: Cannot read property 'background' of undefined
WARN scene: @Commons/Border.qml[25:-1]: TypeError: Cannot read property 'polkit.border-alpha' of undefined
```

## Root cause

Qt 6.12 added a `Color` singleton to QtQuick — https://doc.qt.io/qt-6.12/qml-qtquick-color.html (`Since: Qt 6.12`, backed by `QQuickColor` in `private/qquickcolor_p.h`, exported as `QtQuick/Color 6.12`).

Every shell file does an unversioned `import QtQuick`, which resolves to 6.12, and that built-in wins over `qs.Commons.Color`. The QML engine then hands back the QtQuick singleton:

```
$ /usr/lib/qt6/bin/qml --version
Qml Runtime 6.12.0

// bare QtQuick import, no quickshell, custom singleton also named Color
console.log(String(Color))     // QQuickColor(0x...)
console.log(Color.foreground)  // undefined
console.log(Color.marker)      // undefined
```

Minimal reproduction with no quickshell, a module that exports `singleton Color`, and an unversioned `import QtQuick`:

```
import QtQuick
import MyModule          // exports `singleton Color 1.0 Color.qml`
QtObject { Component.onCompleted: console.log(String(Color), Color.foreground) }
// => QQuickColor(0x...) undefined
```

Evidence that this is the 6.12 upgrade and not a pre-existing problem, from the user journal:

| window | count of `Cannot read property 'border' of undefined` |
| --- | --- |
| 2026-10-08 00:00 → 13:25 (before the upgrade) | **0** |
| 2026-10-08 13:25 → 15:00 | **30,604** |

Pinning the import below 6.12 restores the singleton immediately:

```
import QtQuick 6.11
import qs.Commons
console.log(String(Color), Color.bar.text)  // Color_QMLTYPE_8(0x...) #cacccc
```

Note `import QtQuick 2.15` is also unaffected; only unversioned imports resolve to 6.12.

## Impact

- Bar renders blank/black; `SUPER + SPACE` menu never appears or paints an empty black rectangle.
- `omarchy-menu` IPC still answers `ok`, so the CLI looks healthy while the UI is unusable.
- Lock screen, polkit agent and every panel are affected the same way, since they all read `Color.*`.
- Anyone on `omarchy` + Qt 6.12 hits this on every shell start; it is not self-healing and survives restarts.

## Suggested fix

Rename the singleton away from `Color` so QtQuick can never shadow it again — e.g. `Palette` in `shell/Commons/qmldir` plus a `grep -ro '\bColor\.'` sweep across `shell/`, `themes/` and the shipped plugins. That is robust against future QtQuick additions too.

If renaming is too invasive for now, pinning the import is a one-line-per-file workaround:

```
sed -i -E 's/^([[:space:]]*)import QtQuick[[:space:]]*$/\1import QtQuick 6.11/' $(grep -rlE '\bColor\.' shell --include=*.qml)
```

(54 files in 4.0.4.) Worth noting for anyone else affected: the same collision applies to any user plugin that reads `Color.*`, so a rename needs to consider third-party plugins as well.

## Diagnostics

`omarchy version` → `4.0.4-1`
`quickshell --version` → `Quickshell 0.3.1 (revision , distributed by Arch Linux)`
`/usr/lib/qt6/bin/qml --version` → `Qml Runtime 6.12.0`
`pacman -Q qt6-base qt6-declarative` → `6.12.0-2`, `6.12.0-1`

Screenshots of the broken bar/menu versus the same build with the import pinned are available on request.