Light up table of contents in beamer

Question

I am trying to color ToC in beamer. By default when ToC appears all entries are gray, but I want them to becoloured as my theme. How can this been done?

A MWE is the following

\documentclass[slidestop,compress,mathserif,11pt,xcolor=dvipsnames]{beamer}
\definecolor{LHCblue}{RGB}{4, 114, 255}
\usecolortheme[named=LHCblue]{structure}
\usepackage[bars]{beamerthemetree} %Beamer theme v 2.2
\usepackage{kerkis}
\setbeamercovered{higly dynamic}
\usetheme{Ilmenau} % Beamer theme v 3.0
\useoutertheme[subsection=true]{smoothbars}%Beamer Outer Theme-circles on top
\usefonttheme{serif}
\useinnertheme{circles} %rectangle bullet points instead of circle ones
\usepackage{beamerthemebars}
\title[Short Title]{Full Title}
\author{Author}
\institute{Institute}

\begin{document}

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

\begin{frame}
\frametitle{Contents}
\tiny{\tableofcontents[currentsection]}
\end{frame}

\section{first section}
\begin{frame}
Intro to section
\end{frame}

\subsection{first subsection}
\begin{frame}
Theory
\end{frame}

\subsection{second subsection}
\begin{frame}
Experiment
\end{frame}

\subsection{third subsection}
\begin{frame}
Results
\end{frame}

\section{Back up slides}

\begin{frame}
1st Back up slide
\end{frame}

\begin{frame}
2nd Back up slide
\end{frame}

\begin{frame}
3rd Back up slide
\end{frame}

\end{document}

Answer 1

The ToC inherits the color from your theme; the problem is that you are using

\tableofcontents[currentsection]

before the first \section command, so there's no current section to highlight, so all the information is shaded. Simply remove [currentsection]:

\documentclass[t,compress,11pt,xcolor=dvipsnames]{beamer}
\definecolor{LHCblue}{RGB}{4, 114, 255}
\usecolortheme[named=LHCblue]{structure}
\usepackage[bars]{beamerthemetree} %Beamer theme v 2.2
\usefonttheme[onlymath]{serif}
\usepackage{kerkis}
\setbeamercovered{higly dynamic}
\usetheme{Ilmenau} % Beamer theme v 3.0
\useoutertheme[subsection=true]{smoothbars}%Beamer Outer Theme-circles on top
\usefonttheme{serif}
\useinnertheme{circles} %rectangle bullet points instead of circle ones
\usepackage{beamerthemebars}

\setbeamerfont{section in toc}{size=\tiny}
\setbeamerfont{subsection in toc}{size=\tiny}

\title[Short Title]{Full Title}
\author{Author}
\institute{Institute}

\begin{document}

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

\begin{frame}
\frametitle{Contents}
\tableofcontents
\end{frame}

\section{first section}
\begin{frame}
Intro to section
\end{frame}

\subsection{first subsection}
\begin{frame}
Theory
\end{frame}

\subsection{second subsection}
\begin{frame}
Experiment
\end{frame}

\subsection{third subsection}
\begin{frame}
Results
\end{frame}

\section{Back up slides}

\begin{frame}
1st Back up slide
\end{frame}

\begin{frame}
2nd Back up slide
\end{frame}

\begin{frame}
3rd Back up slide
\end{frame}

\end{document}

Or, setting the subsection in toc color, to use a shading of LHCblue:

\documentclass[t,compress,11pt,xcolor=dvipsnames]{beamer}
\definecolor{LHCblue}{RGB}{4, 114, 255}
\usecolortheme[named=LHCblue]{structure}
\usepackage[bars]{beamerthemetree} %Beamer theme v 2.2
\usefonttheme[onlymath]{serif}
\usepackage{kerkis}
\setbeamercovered{higly dynamic}
\usetheme{Ilmenau} % Beamer theme v 3.0
\useoutertheme[subsection=true]{smoothbars}%Beamer Outer Theme-circles on top
\usefonttheme{serif}
\useinnertheme{circles} %rectangle bullet points instead of circle ones
\usepackage{beamerthemebars}

\setbeamerfont{section in toc}{size=\tiny}
\setbeamerfont{subsection in toc}{size=\tiny}
\setbeamercolor{subsection in toc}{fg=LHCblue!40!black}

\title[Short Title]{Full Title}
\author{Author}
\institute{Institute}

\begin{document}

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

\begin{frame}
\frametitle{Contents}
\tableofcontents
\end{frame}

\section{first section}
\begin{frame}
Intro to section
\end{frame}

\subsection{first subsection}
\begin{frame}
Theory
\end{frame}

\subsection{second subsection}
\begin{frame}
Experiment
\end{frame}

\subsection{third subsection}
\begin{frame}
Results
\end{frame}

\section{Back up slides}

\begin{frame}
1st Back up slide
\end{frame}

\begin{frame}
2nd Back up slide
\end{frame}

\begin{frame}
3rd Back up slide
\end{frame}

\end{document}

If you want table of contents at the beginning of each section, you can use something like

\AtBeginSection[]
{
\begin{frame}<beamer>
\frametitle{Outline}
\tableofcontents[currentsection]
\end{frame}
}

in the preamble.