Mint-Y Dark Themes Cause Unreadable Text in LibreOffice Math (PPA version)

Distribution

Mint 22.1

Package version

Cinnamon 6.4.8

Graphics hardware in use

AMD Radeon RX 5600 XT

Frequency

Always

Bug description

When using Mint-Y dark system themes within the Cinnamon desktop environment on Linux Mint, a display issue occurs specifically in the LibreOffice Math formula editor. The text displayed and typed in the input area is rendered in black, which, against the dark background inherited from the system theme, makes the text nearly invisible and the editor unusable.

This issue does not occur with the version of LibreOffice that comes pre-installed by default with Linux Mint. However, the problem appears consistently after adding the official LibreOffice 'fresh' PPA (ppa:libreoffice/ppa) and upgrading LibreOffice to a newer version available through that PPA.

Changing between different Mint-Y dark themes within the Cinnamon system settings does not resolve the issue. Interestingly, changing specific theme settings within LibreOffice itself (via Tools > Options > Appearance) can sometimes mitigate or partially resolve the problem, suggesting a potential interaction issue between the newer LibreOffice version's rendering engine (VCL: gtk3 in this case) and how the Mint-Y dark theme provides color information to applications.

There have been some reports/discussions online suggesting that Mint-Y themes, particularly the dark variants, may not always communicate color or styling settings perfectly to some applications, which could be related to this issue.

The expected behavior should be that the text in the formula editor is easily readable, ideally rendered in a light color (like white) when a dark system theme is active. The current situation forces users to seek application-specific workarounds instead of the system theme handling the color contrast appropriately.

Steps to reproduce

1. Install Linux Mint 22.1 with the Cinnamon desktop.
2. Set a Mint-Y dark system theme (e.g., Mint-Y-Aqua-Dark, Mint-Y-Dark) in the Cinnamon System Settings > Themes.
3. Add the LibreOffice 'fresh' PPA (ppa:libreoffice/ppa) and upgrade LibreOffice to the latest version available through the PPA.
4. Open LibreOffice Math.
5. Observe the text color in the main formula editor input area.
   screenshot here: showcase problem

Expected behavior

The text in the LibreOffice Math formula editor input area should be clearly visible against the background, adapting to a light color (e.g., white) when a dark system theme is active.

Additional information

• Linux Mint Version: 22.1 cinnamon
  

• Affected Themes: Mint-Y dark variants (e.g., Mint-Y-Aqua-Dark, Mint-Y-Dark).
  

• LibreOffice Version (from PPA where issue occurs): Version: 25.2.3.2 (X86_64) / LibreOffice Community Build ID: 520(Build:2) CPU threads: 16; OS: Linux 6.8; UI render: default; VCL: gtk3 Locale: el-GR (en_US.UTF-8); UI: en-US Ubuntu package version: 4:25.2.3-0ubuntu0.24.04.1~lo1 Calc: threaded (Note: The issue is NOT present with the default LO version shipped with Mint before PPA upgrade)
  

• Workaround: Changing themes/colors within LibreOffice's own Appearance settings (Tools > Options > View / Appearance) can sometimes provide a workaround, but this is application-specific.
  

• Screenshots: Screenshots demonstrating the unreadable text will be attached to this bug report.
  

• This issue seems to point towards how Mint-Y dark themes interact with certain applications (specifically, newer versions of LibreOffice using GTK3 VCL) in providing color information, leading to poor contrast in specific UI elements like the LO Math editor.

Start by reproducing the issue with Linux Mint 22.1, a Mint-Y dark theme, Cinnamon, and the LibreOffice fresh PPA, then compare the affected and preinstalled LibreOffice versions. No repository file or test is named; done means identifying whether Cinnamon supplies the incorrect editor colors and confirming readable formula-editor text without an application-specific workaround.