列表环境中的转义环境减少字符之间的水平空间

Question

为什么转义环境会减少字符之间的水平空间？我尝试了和escapechar。escapeinside请参阅下面的代码。

\documentclass{article}

\usepackage{xcolor}
\usepackage{listings} 

\begin{document}

\begin{lstlisting}[escapechar=@]
    NEW: HardwareVersion 75.32.2 FirmwareVersion 532.23
    OLD: @\textcolor{red}{HardwareVersion 15.32.2}@ FirmwareVersion 323.12
\end{lstlisting}

\begin{lstlisting}[escapeinside={@}{@}]
    NEW: HardwareVersion 75.32.2 FirmwareVersion 532.23
    OLD: @\textcolor{red}{HardwareVersion 15.32.2}@ FirmwareVersion 323.12
\end{lstlisting}

\end{document}