Chapter title in a colored box (custom chapter command)

I try to put my document’s title in a colored box. I looked for it on google and on this forum but I didn’t find anything I like (titleformat, …). I’ve already renew the chapter command (in my .sty file) and I would like to find a way to put the colored box in this renewed command… Unfortunately, I have a lot to learn yet and to understand in Latex 🙁

% Chapter Title redefinition
renewcommand{chapter}{if@openrightcleardoublepageelseclearpagefi%
                    thispagestyle{plain}%
                    @startsection{chapter}{0}{z@}%
                    {-3.5ex @plus -1ex @minus -.2ex}%
                    {2.3ex @plus.2ex}%
                    {noindentfontsize{18}{20}fontspec{Arial}selectfontcolor{my_custom_color}}}

[EDIT]
For now, I’ve that :

And I would like to have that

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Package definition
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
ProvidesPackage{ffgTemplate}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Required Package
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
RequirePackage[a4paper, top=2cm, bottom=2.5cm, left=2.5cm, right=2.5cm]{geometry}  % Gestion des marges
RequirePackage[french]{babel}                                  % Gestion du français
RequirePackage{graphicx}                                       % Gestion des images
RequirePackage{xcolor}                                         % Gestion des couleurs
RequirePackage{hyperref}                                       % Gestion des hyperliens
RequirePackage{fancyhdr}                                       % Gestion des en-têtes et pieds de pages.
RequirePackage{pifont}                                         % Gestion des symbols (ding{55} dans le footer)
RequirePackage{array}                                          % Gestion (améliorée) des tableaux
RequirePackage{ulem}                                           % Gestion (avancée) des soulignements
RequirePackage{textcomp}                                       % Caractères additionnels
RequirePackage{mathtools, amsmath, amstext, amssymb, amsthm}   % Package de l'AMS + mathtools
RequirePackage{gensymb}                                        % symbole degree
RequirePackage{cancel}
RequirePackage{nicefrac}                                       % Gestion des fractions
RequirePackage{xspace}                                         % Gestion intelligente de l'espace après une commande
RequirePackage{lmodern}                                        % Police de caractère
RequirePackage{calc}                                           % Syntaxe naturelle pour les calculs
RequirePackage{framed}
RequirePackage{tcolorbox}                                      % Pour créer des boites colorées.

% Layout fisrt page
RequirePackage{eso-pic}                                % Gestion du background de la page de garde.
RequirePackage[absolute]{textpos}                      % Gestion des positions du texte (option de config : showboxes)
RequirePackage{fontspec}                               % Gestion de "arial" ET "arial narrow" comme font.
RequirePackage{anyfontsize}                            % Gestion des tailles de police hors dictionnaire
RequirePackage{shadowtext}                             % Gestion des ombres
% RequirePackage{UniversalSans}

% Layout Document 
RequirePackage{titlesec}                               % Gestion des sections
RequirePackage{titletoc}                               % Gestion de la table des matière
RequirePackage{titling}                                % Gestion des titres
RequirePackage{enumitem}                               % Gestion des listes

% Tools kit
RequirePackage{fancybox}                               % pour dessiner des boites ;-)
RequirePackage{etoolbox}                               % Renew command & robust command
RequirePackage{float}

% other package
RequirePackage{bm}                                     % Notation mathématique en gras
RequirePackage{lscape}                                 % Gestion du mode "paysage"

frenchbsetup{StandardItemLabels=true}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Define global variable for document
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
deffederationName{F.f.G.}
deffederationAcronym{FfG}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% (Re)Define parametres for document
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
setmainfont{Arial}
addtocaptionsfrench{deftablename{Tableau}}                  % Définition du mot pour les tableaux
addtocaptionsfrench{deffigurename{Figure}}                  % Définition du mot pour les Figures

% Color definition
definecolor{ffg_darkblue}{RGB}{21,29,76}
definecolor{ffg_lightblue}{RGB}{0, 120, 190}
definecolor{ffg_red}{RGB}{241, 83, 60}
definecolor{ffg_title_color}{RGB}{12, 97, 158}
definecolor{footer_color}{RGB}{128, 128, 128}
definecolor{flyingblue}{RGB}{49, 123, 181}
definecolor{greymoreknowledge}{RGB}{200, 200, 200}

% Parametres for TextPos
setlength{TPHorizModule}{1mm}
textblockorigin{5mm}{5mm}                                      % start everything near the top-left corner
setlength{parindent}{0pt}                                     % Pas d'indentation au placement du texte

setlengthfboxrule{0.75pt}
newcommand{mybox}[1]{fbox{$~~~ displaystyle#1 ~~~$}}

newcommandNextYear{%
   advanceyear by 1 theyearadvanceyear by -1}
    

% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Image's first page definition
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
newcommandBackgroundPic{%
    put(0,0){%
        parbox[b][paperheight]{paperwidth}{%
            vfill
            centering
            includegraphics[scale=1]{firstpage.png}%
            vfill
        }
    }
}

shadowoffset{3pt}
shadowrgb{0.8, 0.8, 0.8}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% First Page's definition
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
defmaketitle{%
    null
    thispagestyle{empty}%

    % Titre du document
    begin{textblock}{200}(0,3)
        centering
        {fontsize{33}{42}selectfont {bfseries textcolor{ffg_darkblue}{FORMATION~formationType~discipline}par}}
        {fontsize{33}{42}selectfont {bfseries textcolor{ffg_red}{Module :moduleTitle}par}}
    end{textblock}

    % Type de document
    begin{textblock}{200}(0,8)
        begin{center}
            {fontsize{28}{42}selectfont textcolor{ffg_lightblue}{Formation des Cadres}par}%
        end{center}
    end{textblock}

    % Années
    begin{textblock}{200}(0,11.5)
        centering
        begin{center}
            {fontsize{30}{84}selectfont textcolor{white}{{theyear}hspace{3cm} {NextYear}}par}%
        end{center}
    end{textblock}

    null
    cleardoublepage
}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Other page definition
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% setlength{headheight}{30pt}
fancypagestyle{followingpage}{%
    fancyhf{}

    %% Footer
    fancyfootoffset{3cm}
    fancyfoot[C]{hspace{2.5cm} {fontsize{9}{10}selectfont textit{textcolor{footer_color}{Formation des Cadres~discipline hfill p.thepage hfill Edition theyear~-~NextYear}}} hspace{2.5cm}}
}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Titles layout redefinition
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
makeatletter

% Chapter Title redefinition
renewcommand{chapter}{if@openrightcleardoublepageelseclearpagefi%
                    thispagestyle{plain}%
                    @startsection{chapter}{0}{z@}%
                    {-3.5ex @plus -1ex @minus -.2ex}%
                    {2.3ex @plus.2ex}%
                    {noindentfontsize{18}{20}fontspec{Arial}selectfontcolor{ffg_title_color}}}

% titleformat{chapter}{}{}{0em}{colorbox{blue}{parbox{dimexprtextwidth-2fboxseprelax}{textcolor{white}{thesectionquad#1}}}}
% titleformat{name=section,numberless}
% {normalfontLargebfseries}{}{0em}{colorbox{blue}{parbox{dimexprtextwidth-2fboxseprelax}{textcolor{white}{#1}}}}

% Section Title redefinition
renewcommand{section}{@startsection{section}{1}{z@}%
                        {-3.5ex @plus -1ex @minus -.2ex}%
                        {2.3ex @plus.2ex}%
                        {noindentfontsize{14}{12}fontspec{Arial}selectfontcolor{ffg_lightblue}}}


% SubSection Title redefinition
renewcommand{subsection}{@startsection{subsection}{2}{z@}%
                        {-3.25ex@plus -1ex @minus -.2ex}%
                        {1.5ex @plus .2ex}%
                        {noindentfontsize{13}{20}fontspec{Arial}selectfontcolor{ffg_title_color}}}

makeatother

pagestyle{followingpage}
AtBeginDocument{
    setcounter{secnumdepth}{3}
    setcounter{tocdepth}{3}
    AddToShipoutPicture*{BackgroundPic}
}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Redefine Theoreme & Definition
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
newtheoremstyle{new_theorem_style}
{topsep}       % space before
{topsep}       % space after
{
    itshape
}               % body font
{}              % indent
{bfseries}     % header font
{}              % punctuation
{newline}      % after theorem header
{
    thmname{#1}~thmnumber{#2}thmnote{ - #3}*[-1.5ex]
}% header specification (empty for default)

theoremstyle{new_theorem_style}
newtheorem*{definitionT}{color{ffg_title_color}{Définition}}
newenvironment{definition}
{
    begin{leftbar}
        begin{definitionT}
            mbox{}noindentignorespaces}{
        end{definitionT}
    end{leftbar}
}


% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
% Define colorbox
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %
newtcolorbox{knowledgebox}{colback=ffg_red!5!white, colframe=ffg_red!100!black, fonttitle=bfseries, title={Savoir}, breakable} %breakable
newtcolorbox{skillsbox}{colback=flyingblue!5!white, colframe=flyingblue!100!black, fonttitle=bfseries, title={Savoir faire}, breakable} %breakable
newtcolorbox{morebox}{colback=greymoreknowledge!5!white, colframe=greymoreknowledge!100!black, fonttitle=bfseries, title={Allez plus loinldots}, breakable}
newtcolorbox{dangerbox}[1]{colback=red!5!white, colframe=red!100!black, fonttitle=bfseries, title={Important}, breakable} %breakable

Thank you in advance,

documentclass{book} 
usepackage[T1]{fontenc}
usepackage{xcolor}
usepackage{tabularx} 
usepackage{lipsum}

usepackage[explicit]{titlesec}%
newcommand{bgparbox}[1]{colorbox{blue}{setlength{fboxsep}{6pt}%

begin{tabularx}{dimexprlinewidth-fboxsep}{l>{raggedrightarraybackslash}X}#1end{tabularx}}}
titleformat{chapter}
 {color{white}sffamilybfserieshuge}
 {}
 {0em}
 {bgparbox{thechapter & #1}}%

begin{document}

chapter{Introduction. break A detailed introduction}

lipsum[1] 

end{document} 

definecolor{ffg_title_color}{RGB}{12, 97, 158}
colorlet{shadecolor}{ffg_title_color}
titleformat{chapter}[display]
    {fontsize{16pt}{12pt}selectfontcolor{white}begin{shaded*}}
    {thechapter qquad #1}
    {0pt}
    {end{shaded*}}
titlespacing{chapter}{0cm}{0cm}{0cm}