# How to modify Beamer theme?

Here's a MWE using the Frankfurt theme:

\documentclass{beamer}
\usetheme{Frankfurt}

\usepackage{hyperref}
\usepackage{tikz}
\usepackage{sansmathaccent}
\pdfmapfile{+sansmathaccent.map}
\graphicspath{ {external/} }

\tikz[x=1.2ex, y=1.2ex, baseline=-0.05ex]{%
\begin{scope}[x=1ex, y=1ex]
\clip (-0.1,-0.1)
--++ (-0, 1.2)
--++ (0.6, 0)
--++ (0, -0.6)
--++ (0.6, 0)
--++ (0, -1);
\path[draw,
line width = 0.5,
rounded corners=0.5]
(0,0) rectangle (1,1);
\end{scope}
\path[draw, line width = 0.5] (0.5, 0.5)
-- (1, 1);
\path[draw, line width = 0.5] (0.6, 1)
-- (1, 1) -- (1, 0.6);
}
}

\hypersetup{
allcolors=red
}

\def\blue#1{\text{\color{blue}{#1}}}
\def\red#1{\text{\color{red}{#1}}}
\def\gray#1{\color{gray!50}{#1}\color{black}}

\begin{document}

\section[Using Indifference Curves]{}

\begin{frame}{Deriving a Demand Curve: Step 5 of 5}

\begin{columns}[T]

\begin{column}{0.55\linewidth}
\textbf{STEPS:}
\begin{enumerate}
\item \gray{Let the price of $x$ be $p_0$. Plot an indifference curve and budget line. Mark the equilibrium at $x_0$.}
\item \gray{Drag it down to the diagram below and plot $(x_0,p_0)$.}
\item \gray{Say the price of $x$ falls to $p_1$. Pivot the budget line. Shift the indifference curve outwards and mark the new equilibrium at $x_1$.}
\item \gray{Repeat step (2) and plot $(x_1,p_1)$.}
\item Join the two points. Voila!
\end{enumerate}
\end{column}

\begin{column}{0.45\linewidth}
\begin{center} \begin{tikzpicture}[scale=0.7]
\footnotesize
\draw[->] (0,0) -- (4.2,0) node[right] {$x$};
\draw[->] (0,0) -- (0,4) node[above] {$y$};
\draw (0,0) plot [domain=0.4:3.8] (\x,1.4/\x);
\draw [red] (0,0) plot [domain=0.7:3.8] (\x,2.8/\x);
\draw (0,0) plot [domain=0:2] (\x,-\x*1.4 + 2.8);
\draw [red] (0,0) plot [domain=0:4] (\x,-\x*0.7 + 2.8);

\draw[red,fill] (2.1,1.35) circle [ radius =0.05];
\draw[fill] (1,1.45) circle [ radius =0.05];

\draw [dashed,red] (2.1,-4.5) node[below]{$x_1$} -- (2.1,1.35);
\draw [dashed] (1,-4.5)node[below]{$x_0$} -- (1,1.45);

%second set of axes

\draw[->] (0,-4.5) -- (4.2,-4.5) node[right] {$x$};
\draw[->] (0,-4.5) -- (0,-0.8) node[above] {$p_x$};

\draw[red,fill] (2.1,-3.5) circle [ radius =0.05];
\draw[fill] (1,-2) circle [ radius =0.05];

\draw[red,dashed] (2.1,-3.5) -- (0,-3.5) node[left]{$p_1$};
\draw[dashed] (1,-2) -- (0,-2) node[left]{$p_0$};

\draw[thick] (0.5,-1.3) -- (2.6,-4.2) node[right] {D$_x$};
\draw[->] (-0.3,-2.3) -- (-0.3,-3.2);
\draw[<-] (1.8,-4.7) -- (1.3,-4.7);

\end{tikzpicture}
\end{center}

\end{column}

\end{columns}

\end{frame}

% NewFrame

\end{document}


Here's a picture of the output:

I'd like to modify two things:

(1) In the navigation panel at the top, change the text 'Using Indifference Curves' to green, rather than red.

(2) Change the background color of the frame title row from blue (with white text) to black (with white text).

How do I accomplish these?

• From reading your code, I have the impression that you probably do a lot of things manually to create the 5 steps. This could be automated using overlays. If you'd like you could ask a question showing the code from the 5 steps. – user36296 May 27 '18 at 11:13
• @samcarter I did some research on it. You sir, have changed my life. – Thevesh Theva May 28 '18 at 18:08
• Good to hear! But please don't call me "sir" :) – user36296 May 28 '18 at 18:45

The colour of the section in the headline can be controlled with \setbeamercolor{section in head/foot}{fg=green}, however this only works if you don't disable beamers colour mechanism by setting colorlinks = true.

The frametitle background can be set with \setbeamercolor{frametitle}{bg=black}.

• you don't need to load hyperref with beamer

• please check if you really need \usepackage{sansmathaccent} \pdfmapfile{+sansmathaccent.map}. Many of its definitions are ignored anyway.

\documentclass{beamer}
\usetheme{Frankfurt}