Higher contrast in beamer sidebar with beaver color theme

Question

I am using the beaver color theme, together with a sidebar outer theme, and noticed that a listener standing 10 foot away from the screen wouldn't be able to discern the "not highlighted" sections shown on the side.

Can anyone see the word "Introduction" on the left? (It is there)

How to improve the contrast, perhaps by making these words dark gray, or by making the current section in red, and the "not at the moment" sections in lighter red.

A MWE:

\documentclass[dvipsnames]{beamer}
\usepackage{geometry,xcolor}
\geometry{paperwidth=148mm,paperheight=96mm}
\useoutertheme[width=20mm]{sidebar}
%\usetheme{Berkeley}
\usecolortheme{beaver}
\addtobeamertemplate{navigation symbols}{}{%
\usebeamerfont{footline}%
\usebeamercolor[fg]{footline}%
\hspace{1em}%
\insertframenumber/\inserttotalframenumber
}
\setbeamercolor{footline}{fg=black}
\setbeamerfont{footline}{series=\small}
 % From https://tex.stackexchange.com/a/137028/180429
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage[babel]{csquotes}
\title[]{My presentation title}
\subtitle{Final Project}
\author[]{Euklid} % tricking LaTeX to think that the short title/author is the empty string as represented by []
\institute{Fancy University}
\date{2021}
\begin{document}
\frame{\titlepage}
\section{Background}
\subsection{Introduction}
\begin{frame}{Introduction}{Motivation}
  \begin{center}
    The goal --- study math.
  \end{center}
\end{frame}
\begin{frame}{Method}
The methods for this are...
\end{frame}
\end{document}

Thank you for your feedback. See the new update with more sections and subsections. Now the entries have a larger font when they are selected (and colored), enhancing the visibility. — Simon Dispa, Jun 13 '21 at 23:11
"Introduction" I can see just fine (it's a bit small). The "Background" above it, however, is much harder to see. — Teepeemm, Jun 13 '21 at 23:39

Simon Dispa · Accepted Answer · 2021-06-13T23:08:50.637

You're right, barely visible. The solution increases the font size and makes the shaded text darker.

UPDATED II

(1) To include sections (formerly in white) and subsections, both with a larger font size.

(2) The vertical space between entries in the sidebar was reduced to allow more sections and subsections. Also shaded (gray) sections and subsections have a smaller font size than the selected (colored).

\documentclass[dvipsnames]{beamer}
\usepackage{geometry,xcolor}
\geometry{paperwidth=148mm,paperheight=96mm}
\useoutertheme[width=20mm]{sidebar} %
%\usetheme{Berkeley}
\usecolortheme{beaver}
\addtobeamertemplate{navigation symbols}{}{%
    \usebeamerfont{footline}%
    \usebeamercolor[fg]{footline}%
    \hspace{1em}%
    \insertframenumber/\inserttotalframenumber
}
\setbeamercolor{footline}{fg=black}
\setbeamerfont{footline}{series=\small}
% From https://tex.stackexchange.com/a/137028/180429
%% ************************* added
\makeatletter
\setbeamertemplate{subsection in sidebar}
{%
    \beamer@sidebarformat{5pt}{subsection in sidebar}{\color{darkred!80!gray}\footnotesize\insertsubsectionhead}% color and font size subsection << <<
}
\setbeamertemplate{subsection in sidebar shaded}
{%
    \beamer@sidebarformat{5pt}{subsection in sidebar shaded}{\color{black!60}\scriptsize\insertsubsectionhead}%  color and fontsize <<<
}
\setbeamertemplate{section in sidebar}% color and font size section << <<<
{%
\vbox{%
%       \vskip1ex% <<<<
    \beamer@sidebarformat{3pt}{section in sidebar}{\color{darkred!80!gray}\footnotesize\insertsectionhead}%
}%
}
\setbeamertemplate{section in sidebar shaded}% color and font size section << <<<
{%
\vbox{%
%       \vskip1ex% <<<<
    \beamer@sidebarformat{3pt}{section in sidebar shaded}{\color{black!60}\scriptsize\insertsectionhead}%
}%
}
\makeatother
%% *************************
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage[babel]{csquotes}
\title[]{My presentation title}
\subtitle{Final Project}
\author[]{Euklid} % tricking LaTeX to think that the short title/author is the empty string as represented by []
\institute{Fancy University}
\date{2021}
\begin{document}
    \frame{\titlepage}
\section{Background}
\begin{frame}{Background}{Natural numbers}
    \begin{center}
        [0,] 1, 2, 3, \dots{}
    \end{center}
\end{frame}

\subsection{Introduction}
\begin{frame}{Introduction}{Motivation}
    \begin{center}
        The goal --- study math.
    \end{center}
\end{frame}

\begin{frame}{Method}
    The methods for this are...
\end{frame}

\section{Objective}
\begin{frame}{Objective}{Real numbers}  
Rationals, Integers, Irrationals

\end{frame}

\subsection{Complex numbers?}
\begin{frame}{Next steps}{Complex numbers?}     
Not yet.    
\end{frame}

\subsection{What else?}
\begin{frame}{What else?}{What else?}       
In the horizon.     
\end{frame}

\subsection{A new grant}
\begin{frame}{A new grant}{It will be great!}       
    Everyone will appreciate it.
\end{frame}

\section{Main results so far}
\begin{frame}{Main results so far}{}        
    This is the most important part.        \
\end{frame}

\section{Conclusions}
\begin{frame}{Conclusions}{To be done}      
Not yet completed.
\end{frame}

\section{Thank you}
\begin{frame}{Thank you}{}      
    You all.
\end{frame}


\end{document}

Thanks a lot! But it seems to me that it is more important to darken the text than making it larger. — tush, Jun 07 '21 at 19:50
Can you please add one more command that makes the white text ("Background" in this example) darker? — tush, Jun 07 '21 at 21:30
Thanks a lot! But, one small thing. I now notice that your solution leads also to a bigger space between headings, compared to beamer default definitions without the makeatletter/makeatother addition. I have only 4 sections and 2 subsections, and now the last one is hidden at the bottom. Any idea on how to fix it? — tush, Jun 13 '21 at 20:28

Higher contrast in beamer sidebar with beaver color theme

1 Answers1