\usepackage{tikz}

\setbeamertemplate{frametitle}{} % no titles
\setbeamertemplate{navigation symbols}{\transfade[duration=0.3]} % no navigation symbols

% default colors (black on white)
\definecolor{darkgray}{cmyk}{0.7,0.7,0.7,0}
\definecolor{gray}{cmyk}{0.3,0.3,0.3,0}
\definecolor{lightgray}{cmyk}{0.1,0.1,0.1,0}

\setbeamercolor{background canvas}{bg=white}
\setbeamercolor{normal text}{fg=black}
\setbeamercolor{alerted text}{fg=gray}
\setbeamercolor{section in toc}{fg=gray}
\setbeamercolor{box title}{fg=gray}

\setbeamercolor{block title}{bg=lightgray,fg=black}
\setbeamercolor{block title alerted}{use=block title,fg=red}
\setbeamercolor{block title example}{use=block title}

\setbeamercolor{caption name}{fg=gray}

\setbeamercolor{description item}{fg=gray}

\setbeamercolor{itemize item}{fg=gray}
\setbeamercolor{itemize subitem}{fg=gray}
\setbeamercolor{itemize subsubitem}{fg=gray}

\setbeamercolor{enumerate item}{fg=darkgray}
\setbeamercolor{enumerate subitem}{fg=darkgray}
\setbeamercolor{enumerate subsubitem}{fg=darkgray}

% default font choices
\usepackage{venturis}

\renewcommand{\tiny}{\fontsize{7pt}{8pt}\selectfont}
\renewcommand{\scriptsize}{\fontsize{9pt}{12pt}\selectfont}
\renewcommand{\footnotesize}{\fontsize{10pt}{12pt}\selectfont}
\renewcommand{\small}{\fontsize{12pt}{18pt}\selectfont}
\renewcommand{\normalsize}{\fontsize{14pt}{18pt}\selectfont}
\renewcommand{\large}{\fontsize{16pt}{24pt}\selectfont}
\renewcommand{\Large}{\fontsize{24pt}{37pt}\selectfont}
\renewcommand{\LARGE}{\fontsize{36pt}{48pt}\selectfont}
\renewcommand{\huge}{\fontsize{48pt}{54pt}\selectfont}
\renewcommand{\Huge}{\fontsize{80pt}{96pt}\selectfont}

\setbeamerfont{enumerate item}{size=\LARGE}
\setbeamerfont*{quote}{size=\large,shape=\itshape,series=\bfseries}
\setbeamerfont{word frame}{size=\Huge}

\setbeamertemplate{quote begin}{\begin{tikzpicture}[remember picture,overlay]
	\node[text opacity=0.2,xshift=2cm] at (current page.west) {\fontfamily{ptm}\fontsize{400pt}{96pt}\selectfont ''};
	\end{tikzpicture}}
\setbeamertemplate{quote end}{}

\setbeamertemplate{blocks}[rounded]

\setbeamertemplate{title page}
{
% background image on title page:
%	\begin{tikzpicture}[overlay]
%		\node[inner sep=0pt] at (5.39,-4.45) {\includegraphics[width=1.01\paperwidth]{background_c3}};
%	\end{tikzpicture}
   ~

	\vskip2cm
  {\Large\inserttitle} \\
  \insertsubtitle

  \vskip1.0cm\par
  {\small \insertauthor} \par
  {\small \insertinstitute} \par
  {\small \insertdate}
}

%%% An imageframe has one fullscreen image as background
%%% and maybe some text on top.
\newenvironment{imageframe}[1]
	{
		\setbeamertemplate{background}{%
			\parbox[c][\paperheight]{\paperwidth}{%
				\includegraphics[width=\paperwidth,height=\paperheight]{#1}
		}}
		\begin{frame}
		\color{white}
	}{\end{frame}}

%%% A wordframe has one word (or few) big and centered
\newenvironment{wordframe}
	{
		\begin{frame}
		\bf\usebeamerfont{word frame}
	}{\end{frame}}

%%% A defnframe defines a word or phrase
\newenvironment{defnframe}[1]
	{
		\begin{frame}
      \usebeamerfont{title}\usebeamercolor[fg]{box title}\Large #1: \\
		\vskip0.7cm
		\usebeamercolor[fg]{normal text}\Large\itshape
	}{\end{frame}}

\newcommand{\emptyslide}{\begin{frame}[plain]\end{frame}}