Front Cover for document

Question

I was attempting to get an effect similar to this cover that is found here:

I started with the code found here that draws a grid with colors. How can I go about completing the code to get the output like that shown in the picture above?

Here is the code that I have so far:

\documentclass[11pt,letterpaper]{article}

\usepackage{tikz}
\usetikzlibrary{calc}
\usepackage{graphicx}

\pgfmathdeclarerandomlist{MyRandomColors}{%
    {red}%
    {red!25}%
    {magenta}%
    {magenta!25}%
    {olive}%
    {olive!25}%
    {brown}%
    {brown!10}%
    {violet}%
    {violet!25}%
    {gray}%
    {purple}%
    {yellow}%
    {orange}%
    {orange!25}%
    {cyan}%
    {green}%
}%

\newcommand*{\GridSize}{10}

\newcommand*{\ColorCells}{%
    \foreach \y in {1,...,\GridSize} {
        \foreach \x in {1,...,\GridSize} {
            \pgfmathrandomitem{\RandomColor}{MyRandomColors}
            \draw [fill=\RandomColor, fill opacity=0.2, draw=none, ultra thick]
                (\x-1,\y-1) rectangle (\x,\y);
        }%
    }%
}%

\listfiles
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[scale=1]

    \begin{scope}[thick]
        \ColorCells
        \draw (0, 0) grid (\GridSize, \GridSize);
        \coordinate (input);
    \end{scope}

\end{tikzpicture}

\rotatebox{90}{\textcolor[rgb]{0.01,0.50,1.00}{\fontsize{50}{120}\selectfont{the name of the course}}}
{\fontsize{50}{120}\selectfont{name of authorities}}
\end{document} 

Answer 1

You can overlay the text using TikZ nodes. You can even expand this to fill the entire page using [overlay] and (current page).

\documentclass[11pt,letterpaper]{article}

\usepackage{tikz}
\usetikzlibrary{calc}
\usepackage{graphicx}

\pgfmathdeclarerandomlist{MyRandomColors}{%
    {red}%
    {red!25}%
    {magenta}%
    {magenta!25}%
    {olive}%
    {olive!25}%
    {brown}%
    {brown!10}%
    {violet}%
    {violet!25}%
    {gray}%
    {purple}%
    {yellow}%
    {orange}%
    {orange!25}%
    {cyan}%
    {green}%
}%

\newcommand*{\GridSize}{10}

\newcommand*{\ColorCells}{%
    \foreach \y in {1,...,\GridSize} {
        \foreach \x in {1,...,\GridSize} {
            \pgfmathrandomitem{\RandomColor}{MyRandomColors}
            \draw [fill=\RandomColor, fill opacity=0.2, draw=none, ultra thick]
                (\x-1,\y-1) rectangle (\x,\y);
        }%
    }%
}%

\listfiles
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[scale=1]

    \begin{scope}[thick]
        \ColorCells
        \draw (0, 0) grid (\GridSize, \GridSize);
        \coordinate (input);
    \end{scope}
    \node[rotate=90,above right] at ($(current bounding box.south east)+(-1,1)$)
      {\textcolor[rgb]{0.01,0.50,1.00}{\fontsize{50}{120}\selectfont{the name of the course}}};
    \node[above right] at ($(current bounding box.south west)+(1,1)$)
      {\fontsize{50}{120}\selectfont{name of authorities}};
\end{tikzpicture}