Gwenview Annotate: Clicking on color square does not open color picker (KDE Neon, Wayland, Flatpak version)

[NitramO-YT]

As reported here: https://bugs.kde.org/show_bug.cgi?id=507489

Created attachment 183514 [details]
Visual demonstration of the issue.

SUMMARY:
Cannot open color picker when annotating an image

STEPS TO REPRODUCE:

1. Open Gwenview
2. Open any image
3. Click on "Show Editing Tools" → "Annotate"
4. Select any annotation tool (rectangle, text, pencil, etc.) from the left toolbar
5. Click on the color preview square in the top-left of the Annotate window

OBSERVED RESULT:
Clicking on the color square does nothing.
No color picker opens, no menu or palette appears.
It's not possible to change the color.
There is no way to access the "three-dot" button because the initial color selection UI does not respond.

EXPECTED RESULT:
Clicking on the color square should open a color palette or color picker dialog, allowing the user to choose a color.

SOFTWARE/OS VERSIONS:
Windows: N/A
macOS: N/A
Linux/KDE Plasma: KDE neon User Edition
KDE Plasma Version: 6.4.3
KDE Frameworks Version: 6.16.0
Qt Version: 6.9.1
Kernel Version: 6.14.0-24-generic (64-bit)
Graphics Platform: Wayland

ADDITIONAL INFORMATION:
I am attaching a video that shows the issue.
This bug makes annotation tools unusable if a color change is needed.
I'm using the Flatpak version of Gwenview that comes by default with KDE Neon, by the way.

My kinfo:

• Operating System: KDE neon User Edition
• KDE Plasma Version: 6.4.3
• KDE Frameworks Version: 6.16.0
• Qt Version: 6.9.1
• Kernel Version: 6.14.0-24-generic (64-bit)
• Graphics Platform: Wayland
• Processors: 20 × 13th Gen Intel® Core™ i7-13700H
• Memory: 32 Gio of RAM (31.0 Gio usable)
• Graphics Processor 1: Intel® Graphics
• Graphics Processor 2: NVIDIA GeForce RTX 4060 Laptop GPU

Enregistrement.d.ecran_20250429_193307.webm