Coloring chapters and sections with respect to parts

Question

I am using the book document class and I want to produce a document with several parts, chapters, sections, sections and subsections. I would like to make it easier for the reader by coloring everything with respect to parts. For instance, I would like:

• The title for Part A to be blue
• The chapter titles inside Part A to be blue
• All the heading for the chapter titles in Part A to be blue

and then..

• The title for Part B to be red
• The chapter titles inside Part B to be red
• All the heading for the chapter titles in Part B to be red

etc..

Would anybody be able to help with something like that? Thanks a lot in advance!

PS. The beginning of my document looks like this:

\documentclass[11pt,letterpaper]{book}
\usepackage{amsfonts,amsthm,amssymb}
\usepackage[tbtags]{amsmath}
\usepackage{color}

\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhead[LE,RO]{\slshape\thepage}
\fancyhead[RE]{\slshape \leftmark}
\fancyhead[LO]{\slshape \rightmark}

\renewcommand{\thepart}{\Alph{part}}
\renewcommand{\thechapter}{\Roman{chapter}}

Answer 1

Here' a possible solution using the titlesec package to add the color to the chapter headings; the color for the part headings (and their ToC entries) was added through a redefinition of the internal macros \part, \@part and \@spart; the color for the chapter entries in the ToC was achieved by redefining \@chapter. The color schema was implemente through a simple \ifcase:

\documentclass[11pt,letterpaper]{book}
\usepackage{amsfonts,amsthm,amssymb}
\usepackage[tbtags]{amsmath}
\usepackage{xcolor}
\usepackage{lipsum}
\usepackage{titlesec}
\usepackage{chngcntr}

\newcommand\MyColor{black}

\usepackage{fancyhdr}
\pagestyle{fancy}

\fancyhead[LE,RO]{\slshape\color{\MyColor}\thepage}
\fancyhead[RE]{\slshape\color{\MyColor}\leftmark}
\fancyhead[LO]{\slshape\color{\MyColor}\rightmark}

\counterwithin{chapter}{part}
\renewcommand{\thepart}{\Alph{part}}
\renewcommand{\thechapter}{\Roman{chapter}}

\titleformat{\chapter}[display]
{\normalfont\huge\bfseries\color{\MyColor}}{\chaptertitlename\ \thechapter}{20pt}{\Huge}

\makeatletter
\renewcommand\part{%
  \if@openright
    \cleardoublepage
  \else
    \clearpage
  \fi
  \thispagestyle{plain}%
  \renewcommand\MyColor{%
    \ifcase\value{part} \or blue\or red\or olive\or magenta\else yellow\fi}
  \if@twocolumn
    \onecolumn
    \@tempswatrue
  \else
    \@tempswafalse
  \fi
  \null\vfil
  \secdef\@part\@spart}
\def\@part[#1]#2{%
    \ifnum \c@secnumdepth >-2\relax
      \refstepcounter{part}%
      \addcontentsline{toc}{part}{\color{\MyColor}\thepart\hspace{1em}#1}%
    \else
      \addcontentsline{toc}{part}{\color{\MyColor}#1}%
    \fi
    \markboth{}{}%
    {\centering
     \interlinepenalty \@M
     \normalfont
     \ifnum \c@secnumdepth >-2\relax
       \huge\bfseries\color{\MyColor} \partname\nobreakspace\thepart
       \par
       \vskip 20\p@
     \fi
     \Huge \bfseries #2\par}%
    \@endpart}
\def\@spart#1{%
    {\centering
     \interlinepenalty \@M
     \normalfont
     \Huge \bfseries #1\par}%
    \@endpart}
\def\@chapter[#1]#2{\ifnum \c@secnumdepth >\m@ne
                       \if@mainmatter
                         \refstepcounter{chapter}%
                         \typeout{\@chapapp\space\thechapter.}%
                         \addcontentsline{toc}{chapter}%
                                   {\color{\MyColor}\protect\numberline{\thechapter}#1}%
                       \else
                         \addcontentsline{toc}{chapter}{\color{\MyColor}#1}%
                       \fi
                    \else
                      \addcontentsline{toc}{chapter}{\color{\MyColor}#1}%
                    \fi
                    \chaptermark{#1}%
                    \addtocontents{lof}{\protect\addvspace{10\p@}}%
                    \addtocontents{lot}{\protect\addvspace{10\p@}}%
                    \if@twocolumn
                      \@topnewpage[\@makechapterhead{#2}]%
                    \else
                      \@makechapterhead{#2}%
                      \@afterheading
                    \fi}
\makeatother

\begin{document}

\tableofcontents

\part{Test Part One}
\chapter{Chapter A-One}
\lipsum[1]
\section{Test section A-One One}
\lipsum[1-10]

\chapter{Chapter A-Two}
\lipsum[1]
\section{Test section A-Two One}
\lipsum[1-10]

\part{Test Part Two}
\chapter{Chapter B-One}
\lipsum[1-7]
\chapter{Chapter B-Two}
\lipsum[1-7]

\part{Test Part Three}
\chapter{Chapter C-One}
\lipsum[1-7]
\chapter{Chapter C-Two}
\lipsum[1-7]

\end{document}

Here are some pages of the final document:

And an image of the ToC:

Just as a personal comment, this coloring schema has to be handled very carefully (selecting the appropriate colors is crucial) in order not to become distracting and to avoid achieving an unpleasant layout.

Answer 2

You can modify header formatting using the sectsty package. For example after loading the package, use \partfont{\color{blue}} to change the color of part headings, \chapterfont{\color{blue}} for chapter headings, etc. Other formatting can be applied using this package as well; It might be useful to refer to the sectsty package documentation for other modifiers (font size, font weights, font shape, etc.).

In this case, I define a variable \pcolor so that the color can be changed for each part. Before each part, use \renewcommand\pcolor{} to define the color for the following part; to prevent the color change from affecting the previous section, use \clearpage before changing the color. Page header font color is changed by modifying the fancyhdr definitions.

Here is a MWE showing the changes:

\documentclass[11pt,letterpaper]{book}
\usepackage{amsfonts,amsthm,amssymb}
\usepackage[tbtags]{amsmath}
\usepackage{color}
\usepackage[english]{babel}
\usepackage{lipsum}

\newcommand\pcolor{black}

\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhead[LE,RO]{\slshape\thepage}
\fancyhead[RE]{\color{\pcolor}\slshape \leftmark}
\fancyhead[LO]{\color{\pcolor}\slshape \rightmark}

\renewcommand{\thepart}{\Alph{part}}
\renewcommand{\thechapter}{\Roman{chapter}}

\usepackage{sectsty}
\partfont{\color{\pcolor}}
\chapterfont{\color{\pcolor}}


\begin{document}
\renewcommand\pcolor{blue}
\part{Part 1}

\chapter{Chapter 1}
\lipsum
\chapter{Chapter 2}
\lipsum

\clearpage
\renewcommand\pcolor{red}
\part{Part 2}
\chapter{Chapter 3}
\lipsum
\chapter{Chapter 4}
\lipsum

\end{document}

Here a some snapshots of the output showing chapter header formatting and page header formatting.