Change the color of chapter and section

Question

I have struggle with changing the color of my chapter name and section name.

Here is my work

\documentclass[a4paper,12pt, twoside]{report}
\usepackage[utf8]{inputenc}
    \usepackage[english, vietnamese]{babel}
    \usepackage{wrapfig} 
    \usepackage[dvipsnames]{xcolor}
    \usepackage[top=2cm, bottom=2cm, left=2cm, right=2cm]{geometry}
    \usepackage{color,graphicx,multicol,hyperref,geometry,graphicx,amsmath,tikz,amssymb,pgf,tkz-tab,amsfonts,amsthm,array,fancyhdr}
    \usepackage{lipsum}
    \usepackage{amsxtra, latexsym, amscd, enumerate, ifthen, amstext}
    \usepackage{array, tabularx, longtable}
    \usepackage{mathrsfs}
    \usepackage[all]{xy}
    \usepackage{subcaption}
    \usepackage{csquotes}
    \usepackage{textcmds}
    \DeclareRobustCommand{\divby}{\mathrel{\vbox{\baselineskip.65ex\lineskiplimit0pt\hbox{.}\hbox{.}\hbox{.}}}}
    \DeclareGraphicsExtensions{.pdf,.jpg,.png,.bmp}
    \let\mod=\undefined
    \let\top=\undefined
     \DeclareMathOperator{\im}{Im}
     \DeclareMathOperator{\Ker}{Ker}
    \DeclareMathOperator{\rk}{rank} 
    
    \newtheorem{defi}{Definition}[section]
    \newtheorem{theo}[defi]{Theorem}
    \newtheorem{cor}[defi]{Corollary}
    \newtheorem{lem}{Lemma}[section]
    \newtheorem{prop}[defi]{Proposition}
    \newtheorem{exam}{Example}
    \newtheorem{rema}{Remark}[section]
    \newtheorem{construction}{Construction}[section]
    \newtheorem{prob}{Problem}[section]
    \newtheorem{ques}{Question}
    \newtheorem{exe}{Exercise}
    
    \newcommand{\Np}{\mathbb{N^*}}
    \newcommand{\C}{\mathbb{C}}
    \newcommand{\Z}{\mathbb{Z}}
    \newcommand{\N}{\mathbb{N}}
    \newcommand{\Q}{\mathbb{Q}} 
    \newcommand{\R}{\mathbb{R}} 
    \newcommand{\pr}{\textnormal{P}}
    \newcommand{\E}{\textnormal{E}}
    \renewcommand{\baselinestretch}{1.3}
    \newcommand{\parallelsum}{\mathbin{\!/\mkern-5mu/\!}}
    \newcommand{\B}{\hfill$\qedsymbol$}
    \usepackage{centernot} 
    \usepackage{indentfirst}
    \usepackage{setspace}
    \usepackage[shortlabels]{enumitem}
    %\setlist{leftmargin=5mm}
    %Tạo frame
    \usepackage[most]{tcolorbox}
    %\renewcommand\familydefault{\sfdefault}
    %san - mathversion
    %\DeclareMathVersion{sans}
    %\SetSymbolFont{operators}{sans}{OT1}{cmbr}{m}{n}
    %\SetSymbolFont{letters}{sans}{OML}{cmbrm}{m}{it}
    %\SetSymbolFont{symbols}{sans}{OMS}{cmbrs}{m}{n}
    %\SetMathAlphabet{\mathit}{sans}{OT1}{cmbr}{m}{sl}
    %\SetMathAlphabet{\mathbf}{sans}{OT1}{cmbr}{bx}{n}
    %\SetMathAlphabet{\mathtt}{sans}{OT1}{cmtl}{m}{n}
    %\SetSymbolFont{largesymbols}{sans}{OMX}{iwona}{m}{n}
    %\sffamily\mathversion{sans}
    \newtcolorbox[auto counter]{problem}[1][]{%
        enhanced,
        breakable,
        colback=white,
        colbacktitle=white,
        coltitle=black,
        fonttitle=\bfseries,
        boxrule=1.25pt,
        titlerule=.2pt,
        toptitle=3pt,
        bottomtitle=3pt,
        title=Problem~\thetcbcounter,
        #1}
    \newtcolorbox[auto counter]{activity}[1][]{%
        enhanced,
        breakable,
        colback=white,
        colbacktitle=white,
        coltitle=black,
        fonttitle=\bfseries,
        boxrule=1.25pt,
        titlerule=.2pt,
        toptitle=3pt,
        bottomtitle=3pt,
        title=Activity~\thetcbcounter,
        #1}
    \usepackage{fancyhdr,lipsum}
    \usepackage{pgfplots}
    \pgfplotsset{compat=1.15}
    \usepackage{mathrsfs}
    \usetikzlibrary{arrows}
    
    \pagestyle{fancy}
    \fancypagestyle{plain}{%
      \renewcommand{\headrulewidth}{0pt}%
      \fancyhf{}%
    }
    \renewcommand{\chaptermark}[1]{%
    \markboth{\bfseries\chaptername
    \ \thechapter.\ #1}{}}
    \fancyhead[R]{\bf \thepage}
    \fancyhead[L]{\leftmark}
    \fancyfoot{}
    
    \usepackage{titlesec}
    \titleformat{\chapter}[display]
      {\bfseries\huge}
      {\filright\huge\chaptertitlename~\thechapter}
      {0.5cm}
      {\titlerule[2.5pt]\vspace{0.1cm}\filright}
      [{\vspace{0.1cm}\titlerule[2.5pt]}]
    
    
    \begin{document}
    \chapter{chapter 1}
    \section{section 1}
    \newpage
    \chapter{chapter 2}
    \end{document}

The result is as follows

How can I change the color of Chapter 1, its title and the section title into blue but still keep the two horizontal lines above and below it? I tried the command \chapterfont{\color{blue}}, but the two lines would disappear. I am new with \LaTeX, so please help me. Thank you very much.

Answer 1

edited to answer comments. This did it for me:

\titleformat{\chapter}[display]
{\bfseries\huge\color{blue}}
{\filright\huge\chaptertitlename~\thechapter}
{0.5cm}
{\color{black}\titlerule[2.5pt]\color{blue}\vspace{0.1cm}\filright}
[{\vspace{0.1cm}\color{black}\titlerule[2.5pt]}]