Displaying errors in colour

Hi, I love language tool, but would love it more if the errors were displayed in colour just like on https://languagetool.org/ front page (with yellow indicating one category of errors, red - another and blue or green yet another one).

Any rumours on programmers’ plans to change it?

Underlining errors with blue and red “ribbons” isn’t the best solution - I can hardly see them.

That’s actually possible, but there’s no user interface for it, so you’ll need to edit .languagetool.cfg manually. For example, adding

errorColors=typographical:#b8b8ff, style:#ffb8b8

will show typographical errors with a blue background and style errors with a red background in the upper part of the LT window. typographical and style are the types that are set in grammar.xml as type=.... Note that you should only edit the languagetool.cfg file when LT is not running.

Hi Daniel,
thank you for your reply.

Unfortunately I’m a complete novice.
Is this the way I should edit the file you write about?

Yes, that looks good.

Check it on your machine and tell me if it works because on mine it doesn’t. I use Windows 10 and edited the file with admin rights, if it matters at all.


It doesn’t work in LibreOffice. You need to contact folks at LibreOffice to change this, but don’t hold your breath. Nobody seems to be interested in fixing the grammar checker interface there.

I just can’t believe it - millions of users do NOT care about something that could revolutionize the way they use Writer every day? :disappointed_relieved:

Anyway, thank you for the suggestion: I’m going to turn to LibreOffice staff.

I was going to make an improvement suggestion on Github about this, but luckily found this thread.


I believe that LanguageTool extension is edited here, in LanguageTool project. Please, correct me if I am wrong.
Since the heavy under-the-hood coding is done, is there any chance of accomodating this request or has this been discussed already?

EDIT - Or apply the color changes just to the underline. That could be easier to suit LO interface.

We’re limited by the LibreOffice API. It only takes the information of the error position, we cannot specify a color there, neither for the underline nor for the background.

Case opened in LO’s Bugzilla https://bugs.documentfoundation.org/show_bug.cgi?id=103691:

These would open a lot of possibilities, both for LO and LT.
They could even scale grammar rule by accuracy. Low accuracy rules would just have a light underline tone below the word.

Even better would be to allow type categories to scale warnings. Low accuracy rules could, for example, not be shown in the verify grammar dialog when the user does the final review of the document with F7. I have no idea if it is even possible, nor the ammount of work involved in such change.

Regarding the changable underline colors inside LO, and if there is any interest from you guys in implementing it, later on, I volunteer to try my luck looking into LibreOffice code.
Although they take a lot of time to approve things, if it is easy enough, I maybe be able to make it.

Awesome Marco. Many thanks!

@tiagosantos @dnaber

Áron Budea asked for more information on Bugzilla.

Could someone post there the information he requested?



Why not just link back to this discussion?