Without a graphic-package like tikz or pstrick you can use eso-pic
\documentclass{scrreprt}
\usepackage{xcolor}
\usepackage{eso-pic}
\usepackage{lipsum}
\title{Title}
\author{Name}
\newcommand{\frameattitle}[1][red]{%
\AddToShipoutPictureBG*{\AtTextLowerLeft{%
\color{#1}%
\linethickness{5pt}%
\framebox(\LenToUnit{\textwidth},\LenToUnit{\textheight}){}}%
}%
}
\begin{document}
\frameattitle
\maketitle
\clearpage
\frameattitle
\null\vfill
\begin{center}
\bfseries
Signature
\end{center}
\vfill
\clearpage
\chapter{foo}
\lipsum
\end{document}
In relation to the idea of xport here an example with allows a frame around the text size and the paper size.
EDIT:
I modified my code. Now you can stretch the frame around the text with the setting of the lengths extraxsep and extraysep.
\documentclass{scrreprt}
\usepackage{xcolor}
\usepackage{eso-pic}
\usepackage{lipsum,showframe}
\title{Title}
\author{Name}
\makeatletter
%\frameattext{<backgroundcolor>}{linecolor}{<linewidth>}
\newdimen\extraxsep
\newdimen\extraysep
\extraxsep=20mm
\extraysep=20mm
\newcommand\frameattext[3]{%
\linethickness{#3}%
\AddToShipoutPicture*{%
\AtTextLowerLeft{%%text-boder
\put(\LenToUnit{-,5\extraxsep},\LenToUnit{-0.5\extraysep}){\color{#1}%
\rule{\dimexpr\textwidth+\extraxsep\relax}{\dimexpr\textheight+\extraysep\relax}}%
\put(\LenToUnit{-,5\extraxsep},\LenToUnit{-0.5\extraysep}){\color{#2}%
\framebox(\LenToUnit{\dimexpr\textwidth+\extraxsep\relax},%
\LenToUnit{\dimexpr\textheight+\extraysep\relax}){}
}
}%
}%
}
%\frameatpage{<backgroundcolor>}{linecolor}{<linewidth>}
\newcommand\frameatpage[3]{%
\linethickness{#3}%
\AddToShipoutPicture*{%
\AtPageLowerLeft{%%page-border
\put(0,0){\color{#1}\rule{\paperwidth}{\paperheight}}%
\put(\LenToUnit{\@wholewidth},\LenToUnit{\@wholewidth}){%
\color{#2}\framebox(\LenToUnit{\dimexpr\paperwidth-2\@wholewidth\relax},%
\LenToUnit{\dimexpr\paperheight-2\@wholewidth\relax}){}%
}%
}%
}%
}
\makeatother
\begin{document}
\frameattext{green}{blue}{10pt}
\maketitle
\clearpage
\frameatpage{yellow}{red}{6pt}
\null\vfill
\begin{center}
\bfseries
Signature
\end{center}
\vfill
\clearpage
\frameatpage{yellow}{red}{6pt}
\chapter{foo}
\lipsum
\end{document}
enter image description here
