Nsight Eclipse Edition 10.2: switching appearance theme keeps old background in source code window

I have changed the theme from GTK to Dark. It works fine except for the source code windows.
The background remains white, and the new font colours are barely readable on it.
See picture with example and some context info.

Is there any workaround/solution to switch the theme in full? Thanks in advance.

In the past (2017) this was fixed by tweaking the syntax colouring options for C++, but it was a side effect of changing the highlight mode – look at the pictures in Changing the colour of CUDA code's highlight in Nsight Eclipse Edition. In my case I have disabled ‘semantic highlighting’ for all languages in Window > Preferences > C/C++ > Editor > Syntax Coloring to no effect for the background. This is the only feature that I can actually enable/disable in that context.