Διάστιχο αλλαγή σε συγκεκριμένο τμήμα του κειμένου. Change line spacing inside the document - TeX - LaTeX Stack Exchange

Change line spacing inside the document - TeX - LaTeX Stack Exchange: This is my code

\documentclass[12pt,a4paper]{book}
\renewcommand{\baselinestretch}{1.5}
\begin{document}
\include{Chapter1}
\end{document}
I have please a question:

I would change the line sp...

You can use \setstretch{}. If you want to only affect a certain content you can use it with a group.

You can also apply any size changing switches such as \small or \tiny inside the {} group as well.

Code

\documentclass[12pt,a4paper]{book} 
\usepackage{xcolor}
\usepackage{lipsum}
\usepackage{setspace}

\renewcommand{\baselinestretch}{1.5} 

\begin{document}
\lipsum[1]
{\setstretch{1.0}\color{blue}
\lipsum[2]
}
\lipsum[3]
\end{document}