I've been experimenting with coloured swatches around the page number to indicate the chapter using KOMA and TikZ; each chapter also has an em-dash above the text in the same colour as a stylistic flair. The colour is defined prior to each chapter using \chaptercolor{colorname}, where \chaptercolor is defined as \newcommand{\chaptercolor}[1]{\colorlet{chaptercolor}{#1}}.
The \chaptercolor command has to be called before the chapter to set the line swatch, but this results in the colour swatch for the previous page also changing. I also tried creating a second \swatchcolor command to change the swatches separately to the chapter line mark, and that results in the page before a new chapter getting whatever the default colour for the swatch is.
How can I avoid this?
I've tried various combinations of KOMA options (e.g. cleardoublepage, open) and none of them seem to have the effect I'm after. Not even adding \clearpage before \colorlet in the definition of \chaptercolor seems to work. Here's a MWE that almost works.
\documentclass{scrbook}
\usepackage{scrlayer-scrpage}
%% KOMA options
\KOMAoption{chapterprefix}{true}
\KOMAoption{cleardoublepage}{empty}
\KOMAoption{DIV}{12}
\KOMAoption{draft}{false}
\KOMAoption{fontsize}{11pt}
\KOMAoption{headings}{normal}
\KOMAoption{open}{any}
\KOMAoption{paper}{a4}
\KOMAoption{parskip}{half}
\KOMAoption{twoside}{semi}
\KOMAoption{titlepage}{false}
%% Subfiles for shared preambles
\usepackage[math]{blindtext}
%% Colours - put this before typography so additional named colours can be defined.
\usepackage[table]{xcolor}
\colorlet{darkblue}{blue!40!black}
\usepackage{tikz}
\tikzset{%
small wedge/.pic={
\fill (0, 0) -- ++(-1.2, 0) -- ++(0, 0.6) -- ++(0.6, 0) -- ++(0, 0.6) -- ++(0.6, 0) -- cycle;
},
}
\setkomafont{pagehead}{\small\color{darkblue}\selectfont}
\setkomafont{pagenumber}{\small\color{darkblue}\selectfont}
% Chapters are now "Tutorials"
% Chapters have an em-dash that is \chaptercolor
\newcommand{\chaptercolor}[1]{\colorlet{chaptercolor}{#1}}
\chaptercolor{white}
\renewcommand*{\chapapp}{Tutorial}
\renewcommand*{\chapterheadstartvskip}{\vspace*{-\topskip}}
\renewcommand\chapterformat{{\fontsize{50}{50}\upshape\selectfont\textcolor{chaptercolor}{—}\par\nobreak\chapapp~\thechapter}}
%% Use this to set up the headers and footers
\DeclareNewLayer[
bottommargin,
background,
evenpage,
mode=picture,
contents={%
\putLR{%
\begin{tikzpicture}[remember picture, overlay]
\path pic[fill=chaptercolor, transform shape] at (0,0) {small wedge};
\node[align=right] at (-10mm, 10mm) {\pagemark};
\end{tikzpicture}
}
}]{wedge.even}
\DeclareNewLayer[
bottommargin,
background,
oddpage,
mode=picture,
contents={%
\putLL{%
\begin{tikzpicture}[remember picture, overlay]
\path pic[fill=chaptercolor, transform shape, xscale=-1] at (0,0) {small wedge};
\node[align=left] at (10mm, 10mm) {\pagemark};
\end{tikzpicture}
}
}]{wedge.odd}
\AddLayersAtBeginOfPageStyle{scrheadings}{wedge.odd,wedge.even}%
\pagestyle{scrheadings}
\renewcommand*{\chapterpagestyle}{scrheadings}
\clearscrheadfoot
\lohead{This is a test}
\rehead{\leftmark}
\DeclareGraphicsExtensions{.pdf,.png,.jpg}
% % Metadata goes here
\titlehead{Test document}
\subject{Test subject}
\title{Testing of page number colors}
\makeatletter
\let\thetitle\@title
\let\theauthor\@author
\let\thedate\@date
\makeatother
\begin{document}
\frontmatter
\maketitle
\tableofcontents
\mainmatter
\setcounter{secnumdepth}{1}
\chaptercolor{cyan!50}
\chapter{The first chapter of this work}
\blindtext
\blindmathpaper
\blindtext
\chaptercolor{magenta!50}
\chapter{Another chapter to test this thing}
\blindmathpaper
\Blinditemize
\blindtext[10]
\chaptercolor{orange!50}
\chapter{Another chapter to test this thing}
\blindmathpaper
\Blindenumerate
\blindtext[12]
\chaptercolor{green!50}
\chapter{Another chapter to test this thing}
\blindmathpaper
\Blinddescription
\blindtext[20]
\end{document}
I've based parts of my MWE on other questions, but I haven't found or figured out a solution that does exactly what I'm after. Upon further reflection, I like the idea of being able to set both colours separately, but the important thing is that the colour change must only take effect after a new chapter.
