Consider this MWE:
\documentclass[t]{beamer}
\setbeamercolor{frametitle}{fg=white, bg=blue}
\setbeamercolor{block body}{fg=white, bg=red}
\setbeamercolor{block title}{fg=white, bg=green}
\setbeamertemplate{frametitle}{%
\begin{beamercolorbox}[wd=\textwidth, ht=0.5cm, dp=0.2cm]{frametitle}
\usebeamerfont{frametitle}\insertframetitle
\end{beamercolorbox}
}
\begin{document}
\begin{frame}{This is the frame title}
\begin{block}{Block title}
This is the block content
\end{block}
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus
elit, vestibulum ut, placerat ac, adipiscing vitae, felis. Curabitur
dictum gravida mauris.
\end{frame}
\end{document}
Which yields:

I can make the colorbox containing the frametitle the same width as the normal text by setting the width of the beamercolorbox to \textwidth. How can I make all colored blocks be the same width?
