[Tex/LaTex] Greyscale compatible colours for TikZ

colorprinting

I am looking for five different colours/fill styles for the bars in a TikZ chart. The bars are quite narrow. I want them to be distinctive when viewed onscreen or printed in colour, but also distinctive if the same PDF file gets printed in black and white.

Can anyone recommend a good set of colour definitions? Or some other way of filling the bars to make them distinctive in both scenarios? A bonus (non-essential) would be if colour-blind people could also tell them apart easily.

To clarify, I do not want to produce a greyscale PDF file, or generate a separate output for black and white printing, as I have seen in some other answers. Thanks!

Best Answer

I would suggest using a basic color that you can then mix with different amounts of white and black to create five different shades of this color. In the following example, I have used blue as the base color, but the same can also be done using other colors (such as red and green, as shown in the image below).

\documentclass[a4paper, 12pt]{article}
\usepackage{pgfplots}
\begin{document}

  \begin{tikzpicture}
    \begin{axis}[
        xmin=0,
        xmax=6,
        xtick={1,2,3,4,5},
        ytick={0,5},
        ymin=0,
        ymax=5,
        every axis plot/.append style={
          ybar,
          bar width=10pt,
          bar shift=0pt,
          fill
        }
      ]
      \addplot[blue!15!white]coordinates {(1,5)};
      \addplot[blue!40!white]coordinates{(2,5)};
      \addplot[blue]coordinates{(3,5)};
      \addplot[blue!60!black]coordinates{(4,5)};
      \addplot[blue!15!black]coordinates{(5,5)};
    \end{axis}
  \end{tikzpicture}
\end{document}

The same bar charts converted to grayscale are shown next to the coresponding colored chart in the following image:

Related Solutions

[Tex/LaTex] Optimising TikZ pictures for greyscale printing

You could create you own styles (e.g. afill, bfill, …) and apply them to the area you want to fill. Then you're able to change the style globally or you make two definition files (one for BW and the other for color printing) and you can choose the style by loading one of them vie \include

Indeed that’ll work only for new pictures, but maybe your editor allows searching for fill=red and replace it by afill or something like that

Here’s an example:

% make the definition files (this way just for the example)
\begin{filecontents}{color.tkz}
    \tikzset{%
        afill/.style={fill=red},
        bfill/.style={fill=blue},
    }
    \endinput
\end{filecontents}
\begin{filecontents}{bw.tkz}
    \usetikzlibrary{patterns}
    \tikzset{%
        afill/.style={draw,pattern=crosshatch},
        bfill/.style={draw,pattern=crosshatch dots},
    }
    \endinput
\end{filecontents}

% document begins here ...
\documentclass{minimal}

\usepackage{tikz}
\input{color.tkz}% or \input{bw.tkz}

\begin{document}
\begin{tikzpicture}
    \path [afill] (0,0) rectangle (2,2);
    \path [bfill] (3,0) rectangle (5,2);
\end{tikzpicture}
\end{document}

wich gives either
with color.tkz
or
with bw.tkz

Normally you would make the definitions files by hand. And you can save them in your local texmf-tree to use them with more than one document.

PS: I don’t like cross-hached area an prefer simple grey scales for printing in BW. In this case one can change the definition of the used colors to change them to a grey scale … See the PGF manual, p. 89, last item before section 7.7

Do not use background patterns, like a crosshatch or diagonal lines, instead of colors. They distract. Background patterns in information graphics are evil.

[Tex/LaTex] really greyscale pdf

I don't understand your problem: Here's a version of your MWE that I modified to produce an uncompressed PDF without any fonts embedded (just to make it easier to look at the PDF in a text viewer/editor, it won't affect the colour spaces):

\documentclass[a4paper]{article}
\usepackage{mathptmx} % use times font
\pdfcompresslevel=0   % don't compress the PDF
\pdfmapline{ptmr8r Times-Roman <8r.enc} % don't embed times font
\usepackage[monochrome]{xcolor}

\begin{document}
Hello
\end{document}

If you look at the resulting PDF (eg open it in a text editor) you can see that the text is produced by the following:

stream
0 g 0 G
BT
/F16 9.9626 Tf 139.746 706.129 Td [(Hello)]TJ 154.421 -615.691 Td [(1)]TJ
ET
endstream

The part 0 g 0 G sets the text to /DeviceGray black: this is a pure black, not a rich black. Changing to \usepackage[cmyk]{xcolor} the corresponding code becomes 0 0 0 1 k 0 0 0 1 K which corresponds to a /DeviceCMYK pure black (CMY components are all zero), so still not a rich black.

Adobe acrobat pro preflight and output preview tools agree with me that these options give /DeviceGray black and /DeviceCMYK non-rich black respectively.

So, I think everything is OK with this MWE. Please check with your full document if there is really a problem, and update the MWE to demonstrate it if so.

Best Answer

Related Solutions

[Tex/LaTex] Optimising TikZ pictures for greyscale printing

[Tex/LaTex] really greyscale pdf

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