LaTeX newbie here.
I need to set background color for all my \subsection titles. Whole line should change color, not only the part of it with text.
This does work:
\subsection{\colorbox{Gray}{Title}}
But it does not color whole line. Also I'd like to configure it in a single place for all \subsections.
My google-fu is failing me. Any suggestions on how to do what I want?
To make the \colorbox the width of the line, use \makebox:
\subsection{\colorbox{Gray}{\makebox[\hfill][l]{Title}}}
I'm not 100% sure "\hfill" is what you need to put in the first set of square brackets. You may need to experiment with that part. An alternative worth trying is
\subsection{\colorbox{Gray}{\makebox[\width][s]{Title\hfill}}}
To configure it in one place for all subsections, the easiest thing to do is define a wrapper command:
\newcommand{\mysubsection}[1]
{\subsection{\colorbox{Gray}{\makebox[\hfill][l]{#1}}}}
You could also redefine \subsection, but then you have to learn about the internal commands it uses and take care to match your documentclass's other formatting. I don't recommend it.