[Tex/LaTex] Section title formatting also in the toc

colortable of contentstitlesec

I have searched the web to no avail trying to figure out how to redefine the section title format in a way that will be transmitted to the way that same chapter appears in the Table of Contents.

I would like to define a new environment that alters the colour of the text as well as the section titles as seen in the following minimal example:

\documentclass{article}
\usepackage{xcolor,titlesec}

\newcommand{\mystyle}{}
\titleformat{\section}{\normalfont\Large\bfseries\mystyle}{\thesection}{1em}{}
\newenvironment{myenv}
    {\renewcommand{\mystyle}{\color{red}} \mystyle}
    {\renewcommand{\mystyle}{}}

\begin{document}
\tableofcontents

\section{One}
Section one.

\begin{myenv}
\section{Two}
Section two.
\end{myenv}

\section{Three}
Section three.
\end{document}

This code gives me the below result, which only sets the colour of the section in the text.

what I get

However, what I would like to achieve, without modifying each section manually and without defining a new section command is to have the specific section name appear the same colour in the table of contents too, as seen below.

what I'd like to get

EDIT 1: This post is somewhat related, but it only works if the style of the section titles is changed across the entire document, therefore it does not solve my problem.

EDIT 2: Thanks very much for the really fast answers! However, I think I found the way that works best for me as described in my answer to myself below, inspired by this post.

Best Answer

Here is a solution. I will try to explain if needed.

\documentclass{article}
\usepackage{xcolor}

\newenvironment{myenv}%
   {\color{red}%
   \addtocontents{toc}{\protect\begin{mytocenv}}}%
   {\addtocontents{toc}{\protect\end{mytocenv}}}

\makeatletter 
\let\mtl@section\l@section
\newenvironment{mytocenv}%
   {\renewcommand*\l@section[2]{\mtl@section{{\color{red}##1}}{##2}}}%
   {}
\makeatother
\begin{document}
\tableofcontents

\section{One}
Section one.

\begin{myenv}
\section{Two}
Section two.
\end{myenv}

\section{Three}
Section three.
\end{document}

Update I did not take care of subsection and so on (well that was not explicit in the question) so I think one should do

\makeatletter 
\let\mtl@section\l@section
\let\mt@dottedtocline\@dottedtocline
\newenvironment{mytocenv}%
   {\renewcommand*\l@section[2]{\mtl@section{{\color{red}##1}}{##2}}%
   \renewcommand*\@dottedtocline[5]{\mt@dottedtocline{##1}{##2}{##3}{{\color{red}##4}}{##5}}}%
   {}
\makeatother

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