Cfrgtkky

How can I change the background color of one frame in my Beamer document? I tried doing

begin{frame}

  setbeamercolor{background canvas}{bg=violet}

  % frame contents here

end{frame}

but it seemed to have no effect.

Anyone know what the problem is?

Modify the background canvas before you begin the frame, not within the frame.

To keep the effect of the color change local, you could use curly braces around the frame and that command, or begingroup ... endgroup.

{

setbeamercolor{background canvas}{bg=violet}

begin{frame}

  % frame contents here

end{frame}

}

Put the setbeamercolorcommand outside the frame. This will change the background colour for every subsequent frame. If you want to just change that slide, you can surround the frame and the command in {}

Here's a complete example:

documentclass{beamer}

begin{document}

begin{frame}{A white frame}

end{frame}

% Change all subsequent frames to violet

setbeamercolor{background canvas}{bg=violet!20}

begin{frame}{A violet frame}

end{frame}

begin{frame}{This frame is also violet}

end{frame}

% But this frame only will be yellow: note { ... } around

% the setbeamercolor and the frame to limit the scope 

{setbeamercolor{background canvas}{bg=yellow!20}

begin{frame}{This frame is yellow}

end{frame}

}

begin{frame}{Subsequent frames will be violet}

end{frame}

end{document}

Here's a suggestion to add a bg option to the frame environment, such that background color can be invoked simply by adding the [bg] option to frame.

I have not tested this beyond the template below, put together by piecing random clues here and there. Making the actual color an argument, as in [bg=blue], is left as an exercices to the bored reader.

    documentclass{beamer}



    defbeamertemplate*{background canvas}{mydefault}

    {%

      ifbeamercolorempty[bg]{background canvas}{}{color{bg}vrule widthpaperwidth heightpaperheight}% copied beamer default here

    }



    defbeamertemplate*{background canvas}{bg}

    {%

      color{lightgray!40}vrule widthpaperwidth heightpaperheight% added bg color

    }



    BeforeBeginEnvironment{frame}{%

      setbeamertemplate{background canvas}[mydefault]%

    }



    makeatletter

    define@key{beamerframe}{bg}[true]{%

      setbeamertemplate{background canvas}[bg]%

    }

    makeatother



    begin{document}



    begin{frame}

    frametitle{Normal}

    end{frame} 



    begin{frame}[bg]

    frametitle{With bg}

    end{frame}



    begin{frame}

    frametitle{Normal}

    end{frame}



    end{document}

A similar thing (going off topic now) can be done with an image, instead of plain color:

documentclass{beamer}

usepackage{graphicx}

usepackage{tikz}



pgfdeclareimage[width=paperwidth]{mybackground}{brain}

%% As an option to frame

defbeamertemplate*{background canvas}{mydefault}

{%

  ifbeamercolorempty[bg]{background canvas}{}{color{bg}vrule widthpaperwidth heightpaperheight}% copied beamer default here

}

defbeamertemplate*{background canvas}{image}

{%

    begin{tikzpicture}

        useasboundingbox (0,0) rectangle (thepaperwidth, thepaperheight); 

        pgftext[at=pgfpoint{0cm}{0cm}, left, base]{pgfsetfillopacity{0.1}pgfuseimage{mybackground}}; 

    end{tikzpicture}

}

BeforeBeginEnvironment{frame}{%

  setbeamertemplate{background canvas}[mydefault]%

}

makeatletter

define@key{beamerframe}{image}[true]{%

  setbeamercovered{invisible}%

  setbeamertemplate{background canvas}[image]%

}

makeatother%





title[...]{My title}



begin{document}



begin{frame}[image]

    titlepage

end{frame}



section{Introduction}



begin{frame}[plain]

Text here

end{frame}



end{document}