Colour and links

Adding colour

The xcolor package lets you colour text. Load it, then wrap words:

\usepackage{xcolor}
...
\textcolor{red}{This is red} and \textcolor{blue}{this is blue}.

Built-in names include red, blue, green, orange, gray, and more.

$textcolor prints coloured text and href makes a clickable link$

Highlights and your own colours

\colorbox{yellow}{text} puts a highlight behind the words.
You can even mix your own: \textcolor{red!60}{...} is 60% red (lighter).

Clickable links

The hyperref package turns cross-references and web addresses into clickable links:

\usepackage{hyperref}
...
Visit \href{https://ctan.org}{CTAN} for packages.

Load hyperref last in your preamble — it likes to have the final word.

Common mistakes

Load xcolor for colour and hyperref for clickable links.
Load hyperref last among your packages.

Load xcolor, then make the word warning red with \textcolor{red}{warning}. You need both the package and the command.

\documentclass{article}
\begin{document}
This is a warning you should not ignore.
\end{document}

Click Run to compile and preview the PDF.

Make a clickable link. Load hyperref, then turn the word CTAN into a link with \href{https://ctan.org}{CTAN}. Load hyperref last in the preamble.

\documentclass{article}
\begin{document}
Find thousands of packages at CTAN.
\end{document}