Dica: Imprimindo em preto e branco

Veremos aqui como imprimir documentos em tons de cinza sem ter que alterar as cores do código LaTeX.

Para textos use
\usepackage[monochrome]{xcolor}


Exemplo:

\documentclass[a4paper]{article}
\usepackage{lipsum}
\usepackage[monochrome]{xcolor}
\begin{document}
\color{blue}\lipsum[1]

\color{green}\lipsum[2]
\end{document}

Para figuras TikZ use
\selectcolormodel{gray}


Exemplo:

\documentclass[a4paper]{article}
\usepackage{tikz}
\begin{document}
\pagestyle{empty}

\begin{tikzpicture}[radius=0.5cm]
  \selectcolormodel{gray}
  \fill[red] circle;
  \fill[green] (1,0) circle;
  \fill[blue] (2,0) circle;
\end{tikzpicture}

\begin{tikzpicture}[radius=0.5cm]
  \fill[red] circle;
  \fill[green] (1,0) circle;
  \fill[blue] (2,0) circle;
\end{tikzpicture}
\end{document}

Colorido

Monocromo

Referências: how to create PDF in grayscale mode or TikZ figure only?
How to convert external graphics automatically to black white