schraffierte Tabellenzellen

\documentclass[DIV=14,pagesize]{scrartcl}
\usepackage{geometry}
\usepackage{graphicx}
\usepackage{ngerman}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{xparse}
\usepackage{tabularx}
\usepackage{tikz}
\usetikzlibrary{calc,matrix,patterns,shadings,backgrounds}

\usepackage{xcolor,colortbl}
\usepackage{hhline}
\definecolor{dev}{rgb}{0.63, 0.79, 0.95}
\definecolor{alizarin}{rgb}{0.82, 0.1, 0.26}
\definecolor{amethyst}{rgb}{0.6, 0.4, 0.8}
\definecolor{amber}{rgb}{1.0, 0.75, 0.0}
\definecolor{applegreen}{rgb}{0.55, 0.71, 0.0}
\definecolor{buff}{rgb}{0.94, 0.86, 0.51}
\definecolor{cadmiumorange}{rgb}{0.93, 0.53, 0.18}
\definecolor{caribbeangreen}{rgb}{0.0, 0.8, 0.6}
\definecolor{cerise}{rgb}{0.87, 0.19, 0.39}
\definecolor{carnationpink}{rgb}{1.0, 0.65, 0.79}
\definecolor{cinnabar}{rgb}{0.89, 0.26, 0.2}
\definecolor{darkturquoise}{rgb}{0.0, 0.81, 0.82}
\definecolor{debianred}{rgb}{0.84, 0.04, 0.33}
\definecolor{darkviolet}{rgb}{0.58, 0.0, 0.83}
\definecolor{dollarbill}{rgb}{0.52, 0.73, 0.4}
\definecolor{glaucous}{rgb}{0.38, 0.51, 0.71}
\definecolor{chamoisee}{rgb}{0.63, 0.47, 0.35}
\definecolor{palemagenta}{rgb}{0.98, 0.52, 0.9}
\definecolor{screamingreen}{rgb}{0.46, 1.0, 0.44}
\definecolor{unmellowyellow}{rgb}{1.0, 1.0, 0.4}
\newcolumntype{H}[1]{
  >{\begin{minipage}[c][#1][c]{\linewidth}\centering\strut}
  X
  <{\strut\end{minipage}}
}

\geometry{
 left=0mm,
 right=2mm,
 top=2mm,
 bottom=5mm,
 bindingoffset=2mm
}
\begin{document}
\begin{center}
\setlength\tabcolsep{5pt}
\begin{tabularx}{\linewidth}{*{4}{||H{6cm}}||}
\cellcolor{dev}
\begin{tabular}{m{2.2cm}m{3.3cm}}
 \includegraphics[width=0.4\textwidth]{images/default.png} & \Large{\textbf{ZZ-PS-LL-KR}}   \newline \Large{\textbf{AZ: 1.00}} \newline   
 \Large{\textbf{02.03.2015}} \\ 
\Large{\textbf{Max Mustermann}} & \center{\huge{\textbf{\textcolor{red}{Muster consulting gmbh}}}} \\ 
\end{tabular}
&
\cellcolor{dev}
\begin{tabular}{m{2.2cm}m{3.3cm}}
\includegraphics[width=0.4\textwidth]{images/default.png} & \Large{\textbf{ZZ-PS-CE-VK}} \newline    
\Large{\textbf{AZ: 1.00}} \newline \Large{\textbf{01.09.2004}} \\ 
\Large{\textbf{Nicole Muster}} & \center{\huge{\textbf{MyFIRMA}}} \\ 
\end{tabular}
&
\\ 
\cellcolor{amethyst}
\begin{tabular}{m{2.2cm}m{3.3cm}}
\includegraphics[width=0.4\textwidth]{images/default.png} & \Large{\textbf{ZZ-PS-LL-KR}} \newline    
 \Large{\textbf{AZ: 1.00}} \newline \Large{\textbf{01.02.2009}} \\ 
\Large{\textbf{Thomas Muster}} & \center{\huge{\textbf{MyFIRMA}}} \\ 
\end{tabular}
&
\cellcolor{buff}
\begin{tabular}{m{2.2cm}m{3.3cm}}
  \includegraphics[width=0.4\textwidth]{images/default.png} & \Large{\textbf{ZZ-KS-CO}} \newline      \Large{\textbf{AZ: \textcolor{red}{0.80}}} \newline \Large{\textbf{01.12.2007}} \\ 
 \Large{\textbf{Katja Nüster}} & \center{\huge{\textbf{MyFIRMA}}} \\ 
 \end{tabular}
 &
 \\ 
 \end{tabularx}
 \end{center}
 \end{document}