Tray icon invisible in dark mode/system theme on Ubuntu 24.04 (v4.0.21)

[amal-chandran]

Describe the bug
Tray icon (likely toggler/clock symbol) uses dark colors, making it invisible against dark system tray in dark mode.

Steps To Reproduce

1. Enable dark theme in Ubuntu 24.04 (GNOME Settings > Appearance > Dark).
2. Launch Tockler v4.0.21 → tray icon barely/ not visible in dark tray area.

Expected behavior

• Auto-switch icon to light version in dark mode.
• Or use colorful/contrasting icon always.

Screenshots

System info [attached_file:1]

• OS: Linux 6.14, Ubuntu 24.04.3 LTS (Dark mode enabled)
• Desktop: GNOME (tray extensions?)
• Tockler: v4.0.21 [attached_file:1]