Expanding on to Stephan's post. To make it easy to add keywords to emphasize, it is always best to define a new environment and a command such a \emphasis. Here is a MWE.
![enter image description here][1]
\documentclass{article}
\usepackage{listings,xcolor}
\begin{document}
%% Emphasis
\newcommand\emphasis[2][red]{%
\lstset{emph={#2},
emphstyle={\ttfamily\textcolor{#1}}}}%
\lstnewenvironment{teX}[1][]
{\lstset{language=[LaTeX]TeX}\lstset{%
escapeinside={{(*@}{@*)}},
breaklines=true,
framesep=5pt,
basicstyle=\ttfamily,
showstringspaces=false,
keywordstyle=\ttfamily\textcolor{blue},
stringstyle=\color{orange},
commentstyle=\color{gray!80},
rulecolor=\color{gray!10},
breakatwhitespace=true,
showspaces=false, % shows spacing symbol
xleftmargin=0pt,
xrightmargin=5pt,
aboveskip=0pt, % compact the code looks ugly in type
belowskip=0pt, % user responsible to insert any skips
backgroundcolor=\color{gray!15}, #1
}}
{}
\emphasis{test,aline}
\begin{teX}
% test
\test
\aline
\end{teX}
and another
\emphasis[blue]{new,aline}
\begin{teX}
\new\aline
\end{teX}
\end{document}