\documentclass[10pt,DIV15]{scrartcl}
\usepackage{xcolor}
\usepackage{parskip}
\usepackage{times}
\usepackage{hyperref}
% ----------------------------------------------------------------
% ----------------------------------------------------------------
\begin{document}
% ----------------------------------------------------------------
\title{CMYK-Color overview with xcolor.sty}
\author{Knut Lickert}
\publishers{\url{http://www.lickert.net/TeX/Farbpalette/}}
\maketitle
% ----------------------------------------------------------------
\definecolor{braun}{cmyk}{0.2,0.5,1,0.5}

\newcommand{\text}[4]{
\bgroup
    \xdefinecolor{col#1#2#3#4}{cmyk}{#1,#2,#3,#4}
    \color{col#1#2#3#4}
    #1/#2/#3/#4 \rule{2em}{1ex}
\egroup}
\centering

CMYK-Colors:

\text{0}{0}{0}{0}
\text{0}{0}{0}{1}
\text{0}{0}{1}{0}
\text{0}{0}{1}{1}
\text{0}{1}{0}{0}
\text{0}{1}{0}{1}
\text{0}{1}{1}{0}
\text{0}{1}{1}{1}

\text{1}{0}{0}{0}
\text{1}{0}{0}{1}
\text{1}{0}{1}{0}
\text{1}{0}{1}{1}
\text{1}{1}{0}{0}
\text{1}{1}{0}{1}
\text{1}{1}{1}{0}
\text{1}{1}{1}{1}


\renewcommand{\text}[4]{
\bgroup
    \xdefinecolor{col#1#2#3#4}{cmyk}{.#1,.#2,.#3,.#4}
    \color{col#1#2#3#4}
    #1/#2/#3/#4 \rule{1ex}{1em}
\egroup}

\newcounter{i}  \setcounter{i}{0}
\newcounter{ii} \setcounter{ii}{0}
\newcounter{iii}\setcounter{iii}{0}
\newcounter{iv} \setcounter{iv}{0}


CMYK-Combinations\par
\loop
    \ifnum \value{i}<10 {
        \loop
        \ifnum \value{ii}<10
            {\loop
            \ifnum \value{iii}<10
            {\loop
                \ifnum \value{iv}<10
                    \text{\arabic{i}}{\arabic{ii}}{\arabic{iii}}{\arabic{iv}}
                    \addtocounter{iv}{1}
                \repeat}
                \setcounter{iv}{0}
                \addtocounter{iii}{1}\par
            \repeat}
            \setcounter{iii}{0}
            \addtocounter{ii}{1}\par
        \repeat}
        \setcounter{ii}{0}
        \addtocounter{i}{1}
\repeat
\end{document}