\documentclass{article}
\usepackage{web}
\margins{0pt}{0pt}{0pt}{0pt}   %% Kein Seitenrand
\screensize{150mm}{300mm}      %% Dimensionen: H\"{o}he, Breite des Dokuments

\parindent0pt

\usepackage{pstricks,pstricks-add}

\definecolor{irelandOrange}{HTML}{FF7900}
\definecolor{irelandGreen}{HTML}{009A49}

\begin{document}

\thispagestyle{empty}

\begin{pspicture}(0,0)(30,15)
%% Flagge (Verh\"{a}ltnis 2 Breite : 1 H\"{o}he)
\psframe[linecolor=irelandGreen,fillstyle=solid,fillcolor=irelandGreen](0,0)(10,15)
\psframe[linecolor=white,fillstyle=solid,fillcolor=white](10,0)(20,15)
\psframe[linecolor=irelandOrange,fillstyle=solid,fillcolor=irelandOrange](20,0)(30,15)

\end{pspicture}
\end{document}
