\documentclass{book}
\usepackage{color} 
\usepackage{xepersian}
\makeatletter
\renewenvironment{thebibliography}[1]
     {\chapter*{\hrule height2pt\vspace{5pt}\centering\textcolor{blue}{\bibname}\vspace{5pt}\hrule height2pt}%
 \@mkboth{\MakeUppercase\bibname}{\MakeUppercase\bibname}%
      \if@RTL\if@LTRbibitems\@RTLfalse\else\fi\else\if@RTLbibitems\@RTLtrue\else\fi\fi
      \list{\@biblabel{\@arabic\c@enumiv}}%
           {\settowidth\labelwidth{\@biblabel{#1}}%
            \leftmargin\labelwidth
            \advance\leftmargin\labelsep
            \@openbib@code
            \usecounter{enumiv}%
            \let\p@enumiv\@empty
            \renewcommand\theenumiv{\@arabic\c@enumiv}}%
      \sloppy
      \clubpenalty4000
      \@clubpenalty \clubpenalty
      \widowpenalty4000%
      \sfcode`\.\@m}
     {\def\@noitemerr
       {\@latex@warning{Empty `thebibliography' environment}}%
      \endlist}
\makeatother
\renewcommand\bibname{مراجع}
\makeatletter
%\renewcommand{\@biblabel}[1]{\hspace{-1.5pt}[#1]\hfill}% feel free to change 1.5 
\makeatother
\begin{document}
\begin{thebibliography}{9}
\bibitem{Tix} 
یک مرجع
\end{thebibliography}
\end{document}