# Beamer: framed box for frame title

I prepared the following source

\documentclass[10pt,fleqn,xcolor=svgnames]{beamer}

\setbeamercolor{background canvas}{bg=Green!10}
\setbeamercolor{frametitle}{fg=Brown,bg=Yellow!20}
\setbeamercolor{normal text}{bg=DarkBlue}

\mode<presentation>

\begin{document}
\begin{frame}
\frametitle{Bla Bla}

Bla bla

\end{frame}
\end{document}


with the following result:

I would like to modify a bit the yellow box of the frame title to be framed. I tried using the command \setbeamertemplate but unsuccessfully. It is probably something quite easy, and there are some tips in other topics, but I have not find a way and I'm probably too dumb with beamer! Sorry about that.

\documentclass[10pt,fleqn,xcolor=svgnames]{beamer}

\setbeamercolor{background canvas}{bg=Green!10}
\setbeamercolor{frametitle}{fg=Brown,bg=Yellow!20}
\setbeamercolor{normal text}{bg=DarkBlue}

\usepackage{tcolorbox}

\makeatletter

\setbeamertemplate{frametitle}{%
\ifbeamercolorempty[bg]{frametitle}{}{\nointerlineskip}%
\@tempdima=\textwidth%
\begin{tcolorbox}[colback=Yellow!20,coltext=Brown,enlarge left by=-\beamer@leftmargin,width=\paperwidth]
\usebeamerfont{frametitle}%
\vbox{}\vskip-1ex%
\if@tempswa\else\csname beamer@fteleft\endcsname\fi%
\strut\insertframetitle\strut\par%
{%
\ifx\insertframesubtitle\@empty%
\else%
{\usebeamerfont{framesubtitle}\usebeamercolor[fg]{framesubtitle}\insertframesubtitle\strut\par}%
\fi
}%
\vskip-1ex%
\if@tempswa\else\vskip-.3cm\fi% set inside beamercolorbox... evil here...
\end{tcolorbox}%
}

\makeatother

\begin{document}
\begin{frame}
\frametitle{Bla Bla}

Bla bla

\end{frame}
\end{document}


• Thanks for the attempt. It is quite the think I had in mind, but the frame box should cover completely the page. I would modify your answer myself, but I have not completely understood it yet. – Logos Apr 10 '18 at 18:42
• @Logos please see my edited answer – user36296 Apr 10 '18 at 19:24
• now it's much better. Can you just remove the rounded corners? – Logos Apr 11 '18 at 13:14
• @Logos Have a look at the documentation of the tcolorbox package – user36296 Apr 11 '18 at 13:17
• @Logos You can adjust the appearance of the box by changing the line \begin{tcolorbox}[colback=Yellow!20,coltext=Brown,enlarge left by=-\beamer@leftmargin,width=\paperwidth] – user36296 Apr 11 '18 at 13:19