How could I create a cover page in a report as follows?

Especially I would like to know how to create this grey and red area.
I hope that the following helps you get started. Please provide more details if you want something more help.
This is my MWE using KOMA Script:
\documentclass{scrreprt}
\usepackage{scrpage2,scrextend}
\usepackage{calc}
\usepackage[usenames,dvipsnames]{xcolor}
\usepackage{tikz}
\author{Name A. Surname}
\title{%
\textcolor{BrickRed}{Journal of the} \vspace{1em}\\
Stackexchange \LaTeX users of the world wide web}
% This part depends on your actual environment, Here I am using KOMA script
\makeatletter
\renewcommand{\maketitle}{%
\begin{tikzpicture}[remember picture, overlay]
% Gray boundary
\node (left) at (current page.west)
[rectangle, fill=gray, inner sep=0pt, anchor = west,
minimum width=4cm, minimum height=1\paperheight]{};
% Red boundary
\node (bottom) at (current page.south)
[rectangle, fill=BrickRed, inner sep=0 pt, anchor=south,
minimum width=1\paperwidth, minimum height=0.5cm]{};
% Some additional stuff:
\node [yshift=\paperheight/3] (middle) at (current page.south)
[rectangle, fill=Green, inner sep=0pt, anchor=north west,
minimum height=3cm, minimum width=0.25\paperwidth]{};
\node [yshift=\paperheight/3] (middle) at (current page.south)
[rectangle, fill=BrickRed, inner sep=0pt, anchor=north east,
minimum height=3cm, minimum width=0.25\paperwidth]{};
\node [yshift=\paperheight/3] (middle) at (current page.south)
[rectangle, fill=Goldenrod, inner sep=0pt, anchor=south west,
minimum height=3cm, minimum width=0.25\paperwidth]{};
\node [yshift=\paperheight/3] (middle) at (current page.south)
[rectangle, fill=RoyalBlue, inner sep=0pt, anchor=south east,
minimum height=3cm, minimum width=0.25\paperwidth]{};
\end{tikzpicture}
\thispagestyle{empty}
\parindent0pt
\begin{addmargin}{4em}
\vspace{4cm}
{\huge\usekomafont{title} \@title}
\vspace{2cm}
{\usekomafont{disposition}\Large \@author}
\end{addmargin}
}
\makeatother
\begin{document}
\maketitle
\end{document}

\maketitlemacro (using\renewcommand). TikZ may help you to make the grey and red area, as you can refer to thecurrent pagenode to position a colored rectangular frame. I suggest you to provide a MWE, so that we can help you on detailed points, rather to do all the job for you... – Lionel MANSUY Mar 06 '13 at 15:04