I use KDE neon and recently switched to "Breeze dark" theme. This correctly makes the background colors in Libre Office (including the formula editor in Wirter) dark. However it doesn't change the font color in the formula editor to white (or some other light colour), so I get black font on black background which is invisible.
Steps to Reproduce:
1. Choose "breeze dark" theme on KDE neon (probably does the same with other dark themes and other systems)
2. Open Libre Office Writer
3. Insert > Object > Formula
4. Typed anything
text appears as black on black background (so is not visible)
text should appear as white (or whatever color is specified as primary color by the theme)
User Profile Reset: Yes
Build ID: 60bfb1526849283ce2491346ed2aa51c465abfe6
CPU threads: 8; OS: Linux 4.13; UI render: default; VCL: kde4;
Locale: en-US (en_US.UTF-8); Calc: group
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36 OPR/51.0.2830.55
Arch Linux 64-bit
Build ID: 9c459fd919cb8199a69fc2d630742930e533285b
CPU threads: 8; OS: Linux 4.15; UI render: default; VCL: kde4;
Locale: fi-FI (fi_FI.UTF-8); Calc: group
Built on March 29th 2018
Seems like bug 121380 might be a possible duplicate of this report.
I see the same issue with the Adwaita-dark theme on GNOME3.30.2.
I set the "Document background" to black and the "Font color" to white under "Options -> LibreOffice -> Application Colors" and inserted a formula in Writer by doing Alt-I - O - F to get the formula text entry box. The text in the entry box was white on a black background as expected, and the formula in the Writer page display was also white on a black background. But when I clicked on a blank part of the Writer document to finish entering the formula, the formula switched to black on black.
I haven't found any way to change the color of the finished formula except by putting explicit colors in the formula itself. I don't want to do that since the light color would probably persist even if someone opened the .odt file with LO configured for black text on a white background.
Oops, mine is a related but different bug: black formula text in the *document* rather than in the *editor*. I apologize for the error.
With the KDE5 backend, I don't reproduce the problem, but maybe it is because it does not adapt to the theme yet.
Build ID: 2c7b0030b40de00e8c9ab997bdfe83631861968a
CPU threads: 8; OS: Linux 4.20; UI render: default; VCL: kde5;
Locale: fi-FI (fi_FI.UTF-8); UI-Language: en-US
Created attachment 150385 [details]
Screenshot with kde5
It seems this is now also reproducible with the new kde5 VCL plugin after going to Plasma system settings -> "Workspace Theme" and setting the "Look and Feel" and "Desktop Theme" to "Breeze Dark".
After logging out and in again, it looks as shown in the attached screenshot.
It's actually black font on grey background, so somewhat readable, but not ideal...
Build ID: 28eab5de358631758315a3581e860d6ef533259a
CPU threads: 4; OS: Linux 4.19; UI render: default; VCL: kde5;
Locale: en-GB (en_GB.UTF-8); UI-Language: en-US
Side note: It's just fine in the "Help" -> "About" dialog, for example (white font used there).
I believe this is a duplicate of bug 90297 ?
That bug is more general, as in applies all desktop environments. I.e. this is not fault of qt/kde5 (correct me if I'm using the library names incorrectly, I find this GTK/QT/KDE/Plasma and related libraries thing sometimes confusing).
*** This bug has been marked as a duplicate of bug 90297 ***