Highlighting of Beamer navigation bar

Question

I have an issue with the highlighting of my navigation bar within a beamer presentation. On my computer monitor the highlighting looks quite good, but i like to have the current element of the section/subsection a little bit more distinct because at the beamer there isn't a big difference noticeable.

So my question is, how can i style the current element within the navigation bar? I'm using LaTeX with the Warsaw theme.

My presentation looks like this:

\documentclass[12pt]{beamer}
\usepackage[english]{babel}  
\usepackage[utf8]{inputenc} 
\beamertemplatenavigationsymbolsempty
\setbeamercovered{transparent}
\setbeamertemplate{footline}[]

\usetheme{Warsaw}
\usecolortheme{seahorse}

\title[]{PRJ2 - HB Logistics}

\begin{document}
\begin{frame}
\titlepage
\end{frame}

\begin{frame}
\tableofcontents
\end{frame}

\section{Introduction}
\subsection{Project conditions}
\begin{frame}
\frametitle{Project conditions}
\end{frame}

\end{document}

Answer 1

One option is to change the "opacity" for the shaded sections/subsection, and reduce the default 50% factor used to, say, a 20%:

\documentclass{beamer}
\usetheme{Warsaw}

\setbeamertemplate{section in head/foot shaded}[default][20]
\setbeamertemplate{subsection in head/foot shaded}[default][20]

\begin{document}

\section{Test section one}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\section{Test section two}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}

\end{document}

In the Warsaw theme, sections in the navigation bar are by default, typeset in white over a black background, so in my opinion that is the maximum possible contrast. If you want to change this, you can set the section in head/foot color according to your liking:

\documentclass{beamer}
\usetheme{Warsaw}

\setbeamertemplate{section in head/foot shaded}[default][20]
\setbeamertemplate{subsection in head/foot shaded}[default][20]
\setbeamercolor{section in head/foot}{bg=black!60,fg=orange}

\begin{document}

\section{Test section one}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\section{Test section two}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}

\end{document}

You can also change the font size, but, since the font size used for shaded and current elements are not independent, this will require some additional work:

\documentclass{beamer}
\usetheme{Warsaw}

\setbeamertemplate{section in head/foot shaded}[default][20]
\setbeamertemplate{subsection in head/foot shaded}[default][20]
\setbeamerfont{section in head/foot}{size=\small}
\setbeamerfont{subsection in head/foot}{size=\footnotesize}

\makeatletter
\def\insertsectionnavigation#1{%
  \hbox to #1{%
    \vbox{{\usebeamerfont{section in head/foot}\usebeamercolor[fg]{section in head/foot}%
     \vskip0.5625ex%
     \def\slideentry##1##2##3##4##5##6{}%
     \def\sectionentry##1##2##3##4##5{%
       \ifnum##5=\c@part%
       \def\insertsectionhead{##2}%
       \def\insertsectionheadnumber{##1}%
       \def\insertpartheadnumber{##5}%
       \setbox\beamer@tempbox=\hbox{%
         \hyperlink{Navigation##3}{\hbox to #1{%
             \hskip0.3cm%
             \ifnum\c@section=##1%
               {\usebeamertemplate{section in head/foot}}%
             \else%
               {\tiny\usebeamertemplate{section in head/foot shaded}}%
             \fi\hskip0.3cm}}}%
       \ht\beamer@tempbox=1.6875ex\dp\beamer@tempbox=0.75ex%
       \box\beamer@tempbox\fi}%
     \dohead\vskip0.5625ex}}\hfil}}
\def\insertsubsectionnavigation#1{%
  \hbox to #1{%
    \vbox{{%
      \usebeamerfont{subsection in head/foot}\usebeamercolor[fg]{subsection in head/foot}%
      \vskip0.5625ex%
      \beamer@currentsubsection=0%
      \def\sectionentry##1##2##3##4##5{}%
      \def\slideentry##1##2##3##4##5##6{\ifnum##6=\c@part\ifnum##1=\c@section%
        \ifnum##2>\beamer@currentsubsection%
        \beamer@currentsubsection=##2%
        \def\insertsubsectionhead{##5}%
        \def\insertsectionheadnumber{##1}%
        \def\insertsubsectionheadnumber{##2}%
        \def\insertpartheadnumber{##6}%
        \setbox\beamer@tempbox=\hbox{\beamer@link(##4){%
            \hbox to #1{\hskip0.3cm%
              \ifnum\c@subsection=##2%
                {\usebeamertemplate{subsection in head/foot}}%
              \else%
                {\tiny\usebeamertemplate{subsection in head/foot shaded}}%
              \fi\hfil\hskip0.3cm}}}%
        \ht\beamer@tempbox=1.6875ex\dp\beamer@tempbox=0.75ex%
        \box\beamer@tempbox\fi\fi\fi}%
      \dohead\vskip0.5625ex}\hfil}}}     
\setbeamertemplate{headline}%{split theme}
{%
  \leavevmode%
  \@tempdimb=5.4375ex%
  \ifnum\beamer@subsectionmax<\beamer@sectionmax%
    \multiply\@tempdimb by\beamer@sectionmax%
  \else%
    \multiply\@tempdimb by\beamer@subsectionmax%
  \fi%
  \ifdim\@tempdimb>0pt%
    \advance\@tempdimb by 1.825ex%
    \begin{beamercolorbox}[wd=.5\paperwidth,ht=\@tempdimb]{section in head/foot}%
      \vbox to\@tempdimb{\vfil\insertsectionnavigation{.5\paperwidth}\vfil}%
    \end{beamercolorbox}%
    \begin{beamercolorbox}[wd=.5\paperwidth,ht=\@tempdimb]{subsection in head/foot}%
      \vbox to\@tempdimb{\vfil\insertsubsectionnavigation{.5\paperwidth}\vfil}%
    \end{beamercolorbox}%
  \fi%
}

\makeatother
\begin{document}

\section{Test section one}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\section{Test section two}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}
\subsection{Test subsection}
\begin{frame} test\end{frame}

\end{document}