# transparency in colorbox

I want to define my paragraphs and subsubsections to always be inside of a transparent box with a certain color.

I know that there's a transparency-package but this doesn't work with the PDF-view only with PS-view (i don't really understand why, but it seems that I can't use it for what i want to do), I also found a solution with the package tikz but i don't really understand how it works. Here is an Example where someone uses tikz and gets a transparent box with transparent text (I only want a transparent box - no transparent text).

Until now I only used Latex for writing protocols in a&a Style, so I don't know much about redefining commands and things like that. I am using the document class article with texmaker. I am producing a PDF-workbook for students so I need the solution to be compatible with PDF.

I'm trying to make a minimal example of what I did so far:

\documentclass[a4paper, 12pt, DIV10]{article}

\usepackage[ngerman]{babel}
\usepackage{xcolor}
\usepackage[explicit]{titlesec}
\usepackage{lipsum}

\titleformat{\subsubsection}
{\normalfont\Large\bfseries}
{}
{0em}

\setcounter{secnumdepth}{4}

\titleformat{\paragraph}
{\normalfont\Large\bfseries}
{}
{0em}

\begin{document}

\section{Kapitel}
\lipsum[1]

\subsubsection*{Erklärung}
\lipsum[2]

\paragraph*{Übungen}
\lipsum[3]

\end{document}


I hope you can help me, if I forgot to mention anything let me know, and I'll figure it out.

• Welcome to the site. Your example doesn't give any clue as to why transparency is required, since there is nothing behind the colored boxes. So what are the real requirements? – Steven B. Segletes Jul 28 '16 at 15:46
• maybe transparency wasn't the right word - when I defined my color i got a nice light blue but the color was too 'intense' . I like the shade of this color (don't want to change it) but i want to make it faded (just like in the example - the box in the middle is olive-green and the box above is olive-green as well, but more 'transparent/faded'. However I don't want my text to also become transparent/faded ) – Karfloffel Jul 28 '16 at 15:59
• You don't need all the complications brought about by transparancy to achieve your goal. Complex colors can be built. For example red!40 defines a color that is 40% red, the remainder white, whereas red!40!black is 40% red, 60% black. The complexity knows no bound: red!40!black!60!green, etc. – Steven B. Segletes Jul 28 '16 at 16:54

Two variants:

\documentclass[a4paper, 12pt, DIV10]{article}

\usepackage[ngerman]{babel}
\usepackage{xcolor}
\usepackage[explicit]{titlesec}
\usepackage{lipsum}
\usepackage{tikz}
\titleformat{\subsubsection}
{\normalfont\Large\bfseries}
{}
{0em}

\setcounter{secnumdepth}{4}

\titleformat{\paragraph}
{\normalfont\Large\bfseries}
{}
{0em}

\begin{document}

\section{Kapitel}
\lipsum[1]

\subsubsection*{Erklärung}
\lipsum[2]

\paragraph*{Übungen}
\lipsum[3]

\end{document}


If you want a different opacity for the text:

\documentclass[a4paper, 12pt, DIV10]{article}

\usepackage[ngerman]{babel}
\usepackage{xcolor}
\usepackage[explicit]{titlesec}
\usepackage{lipsum}
\usepackage{tikz}
\titleformat{\subsubsection}
{\normalfont\Large\bfseries}
{}
{0em}

\setcounter{secnumdepth}{4}

\titleformat{\paragraph}
{\normalfont\Large\bfseries}
{}
{0em}

\begin{document}

\section{Kapitel}
\lipsum[1]

\subsubsection*{Erklärung}
\lipsum[2]

\paragraph*{Übungen}
\lipsum[3]

\end{document}


Side remark: In case the DIV10 in your example means that in your real document you aren't using article but a KOMA class, be aware that they don't like titlesec much.

• Thank you for your help, thats exactly what i wanted for the boxes, however the text is also faded, which is exactly what I wanted to avoid. Is there possibly a way to use \pgfsetfillopacity (or just define the opacity) in \definecolor so that it only affects the box? – Karfloffel Jul 28 '16 at 16:17
• @Karfloffel: I edited the answer. – Ulrike Fischer Jul 28 '16 at 16:33