Jasna Kespret 

I guess it's trying to keep some contrast but fails a bit with the bright green.  You can improve it a little by setting the color contrast to the lowest possible in your File -> Options -> Editor.  Gets you this:

Instead of this:

But that could come with other problems depending on the content of the files you are translating.

So you might be better to try Wordbird from the appstore instead which as a plugin does offer more features, and in terms of the highlighting seems to be better wrt the contrast:

In the meantime we'll address the contrast in the Wordlight plugin in an update at some point.

Thank you, dear Paul. For now, Wordlight works fine.
Regards - Jasna

Jasna Kespret ,

I have logged this with the appstore team for improvement in the app UI - internal reference SDLCOM-5940

Thank you,

Oana

Perfect. Thank you. Jasna