Pol wrote:
Is it possible to change the mark for extra space (ctrl-space)?
How to change its color as well, independently from the TeX code color?
I would that mark less visible.
That is not a "extra space", but a "non-breaking space". It is used
for things like "Mr. Somebody" where you don't want a line break to
happen after "Mr."
Nonbreaking spaces are usually not needed that often. How come
you find them too visible? Are you using lots of them to get "extra
space" somewhere? There are usually better ways of getting
extra space. "Insert->Formatting->Horizontal Space" lets you
insert spaces of any length you might need.
Or if you're making indented lists, look at how that is done in
the user guide. For computer code, there is the "listing inset"
to make things easier.
Helge Hafting