\documentclass[14pt]{report}
\usepackage{extsizes}
\usepackage[paperwidth=21cm,paperheight=21cm,left=0.2cm,right=0.2cm,top=0.2cm,bottom=0.2cm]{geometry}
\usepackage{pxfonts}
\pagestyle{empty}
\usepackage{graphicx}
\usepackage{booktabs}
\usepackage[table]{xcolor}
\definecolor{lightgray}{gray}{0.85}
\usepackage{color}
\begin{document}
\begin{table}
  \begin{center}
  \rowcolors{2}{lightgray}{}
  \resizebox*{!}{\textwidth}{
    \begin{tabular}{lp{4.45cm}}
      \toprule
 Parameter   & . output  \\ 
      \midrule
  'ADbar' & $0.2688 \pm 0.0100$  \\ 
  'AUbar' & $\textcolor{blue}{ 1.0000 }$  \\ 
  'Adv' & $\textcolor{blue}{ 1.0000 }$  \\ 
  'Ag' & $\textcolor{blue}{ 1.0000 }$  \\ 
  'Agp' & $0.1661 \pm 0.0100$  \\ 
  'Auv' & $\textcolor{blue}{ 1.0000 }$  \\ 
  'BDbar' & $-0.1273 \pm 0.0040$  \\ 
  'Bdv' & $1.030 \pm 0.060$  \\ 
  'Bg' & $-0.06 \pm 0.27$  \\ 
  'Bgp' & $-0.3831 \pm 0.0100$  \\ 
  'Buv' & $0.810 \pm 0.016$  \\ 
  'CDbar' & $9.6 \pm 1.2$  \\ 
  'CUbar' & $7.06 \pm 0.80$  \\ 
  'Cdv' & $4.85 \pm 0.30$  \\ 
  'Cg' & $5.56 \pm 0.32$  \\ 
  'Cgp' & $\textcolor{blue}{ 25.00 }$  \\ 
  'Cuv' & $4.824 \pm 0.060$  \\ 
  'DUbar' & $1.55 \pm 1.00$  \\ 
  'Euv' & $9.92 \pm 0.80$  \\ 
  'fd' & $\textcolor{blue}{ 1.0000 }$  \\ 
  'fs' & $\textcolor{blue}{ 0.4000 }$  \\ 
      \midrule
  \rowcolor{white}
 Fit status   & \textcolor{red}{ not-a-fit }  \\ 
  \rowcolor{white}
 Uncertainties   & not-a-fit  \\ 
      \bottomrule
    \end{tabular}
  }
  \end{center}
\end{table}

\end{document}
