Topaz, thanks for following up and showing where I was wrong.
They do display differently in several areas. I needed to load up a different dark theme in order to see it (The one I was using is one of my own home-made dark themes). Once I tried Dark Purple, mimicking your screenshot, I saw it.
A different theme. Of course!
I do like Zorin's themes and the Appearance dialog. It's so easy to change the accent color and background. That's not so easy in other distros.
How you fixed this please tell please please please
It's literally a week and Zorin team dont want to see and fix this like then why user will come to zorin user wants fast help and perfect experience in support but it's kinda missing. 
Is it me only or others also want this plaese push an update zorin team i want office it's my main need I have started looking for another linux distro because of office issues in this but the thing stopping me from doing so is the look and feel of zorin os, Please Please zorin team push an update.
Sometimes we have to make tough choices.
Let us know what OS you have chosen. And if the issue happens on
that one or not.
I missed this one... UncleNo.1, have you been searching for the fix online during this week or just waiting for someone here to solve? I see several very nice people have tried to help you. Don't see much thankfulness for their efforts.
But we all show gratitude in different ways.
It'd be funny if uninstalling and reinstalling office fixed the issue.
I didn't choose any! coz no distro is good like zorin but like u can also clearly see that I have mentioned zorin team and literally they dont want to take any action at least they should reply that we are working to fix and because of this only I can easily say zorin os future is not so bright.
I tried all the things here but none of them is end to end fix I mean some are telling to change view that I dont want to do and changing icon is just a timepass still black text is there. 
This is something I've seen several people guess wrong on. Zorin will be around for a long time. The Zorin team is pretty busy right now (It's only 2 people) so as far as priorities, I would think getting Lite, Education, Grid all figured out and working correctly would be at a much higher level. Your patience will be required. We know it's frustrating, you want it the way you want it. But there are a lot more people waiting on Lite, which they paid for. So please, show some patience.
Can you list all the things you've found during your searches to help fix this issue?
All I can say is that the support here is far better than anything I ever had from Microsoft. It's why I'm happy to buy the Pro version to say thanks.
Switching to a new OS is a big thing. I've run into my own issues, and learnt a lot. I still have a way to go to get things set up how I would like, and in other areas I may have to compromise on my preferences.
But it is important to realise that people here are volunteers, and very kind with their time and experiences. Always be grateful and appreciate that position. There's nothing worse than helping people and then having demands made of you that make you feel unappreciated. So always be polite, and patient, and be as clear as you can about what you have tried, what happened as a result - it all helps others to help you. Best wishes!
Yes you are very true
Yes I will be patient I wont disturb lets see if they fixes it or not in a year.
This problem appears in other distros (like Ubuntu) when using a dark application theme. I see it as a LibreOffice problem to fix. It's very limited, does not affect how the program functions, and there are ways presented here to avoid it.
Hello thanks but I have already mentioned in this thread that i need permanent solution no temporary solution.
and its been weeks why libre or zorin or ubuntu no one fixing this do they really know this?
To put your concern into the big picture, there are a ton of LibreOffice bugs reported and to be dealt with. Here you can search their bug reports:
I searched for "dark theme" bugs and here is the list:
This one is probably your issue - check the image attached to it:
They classify it as "medium trivial" and no one is assigned yet to fix it.
Added: If you think this report is the same problem as yours, it needs to be confirmed. You can add to the bug report to do that.
This is piquing my curiosity a bit, to look in the libre source code and figure out why. Too busy with other things at the moment, but will set the idea on the back-burner. Not that it means much. I will probably fail.
Great Job Topaz. 5 Likes from me on this.... but only 1 counts..lol
UncleNo.1, the problem may be with Libreoffice & Not Zorin....
Hope the fix for you is in those links.
Yes maybe
Nope but permanent fix is coming I soon I think so with libreoffice updates.
libreoffice source code is big.
I have had it downloading for an hour and not even half-way through yet.
I have not forgotten this...
I was also wrong earlier, by the way. Libreoffice in Zorin OS is using gtk3.
What it is not using, however... are Unique Style Classes. It is because of this poor implementation, that Libreoffice is notoriously difficult to get to work with any gtk dark theme.
I launched using gtk-inspector (old style: gtk-parasite)
GTK_DEBUG=interactive libreoffice --writer
And was astonished that hovering the pointer on the classes yielded nothing except for the Scrollable Window and Widget. That's pretty much it.
There was no way of defining that actual button in question which has the wrong text color.
In other words... Libreoffice only references a Few most Basic elements in the gtk.css. This very generic approach means that it is impossible for a themer (Or Distro Developer) to "fix." There are no style classes to fix.
The only way to resolve this is to keep pinging the Libreoffice developer.