\documentclass{article}
\usepackage{web}
\margins{0pt}{0pt}{0pt}{0pt}   %% Kein Seitenrand
\screensize{300mm}{450mm}      %% Dimensionen: H\"{o}he, Breite des Dokuments

\parindent0pt

\usepackage{pstricks,pstricks-add}

\definecolor{russiaBlue}{HTML}{0039A6}
\definecolor{russiaRed}{HTML}{D52B1E}


\begin{document}

\thispagestyle{empty}

\begin{pspicture}(0,0)(45,30)
%% Flagge (Verh\"{a}ltnis 3 Breite : 2 H\"{o}he)
\psframe[linecolor=white,fillstyle=solid,fillcolor=white](0,20)(45,30)
\psframe[linecolor=russiaBlue,fillstyle=solid,fillcolor=russiaBlue](0,10)(45,20)
\psframe[linecolor=russiaRed,fillstyle=solid,fillcolor=russiaRed](0,0)(45,10)
\end{pspicture}
\end{document}
