[Tex/LaTex] Bad colors in table using baposter

bapostercolor

I'm trying to assign specific colors to table cells in a poster (baposter). Unfortunately they are reproduced different in the pdf. As they have to match the colors of my graphs I need precisely the specified ones.
In my presentation (beamer class) the colors are reproducing nicely using the same code. Therefore I assume the table and use of \cellcolor is fine.

Please find a working example below:

\documentclass[a0paper,portrait]{baposter}
\usepackage{relsize} % Used for making text smaller in some places
\usepackage{color, colortbl}  % define own fancy colours
\graphicspath{{figures/}} % Directory in which figures are stored

\definecolor{VeryCold}{HTML}{000000}  % becomes 231F20 in the pdf
\definecolor{Cold}{HTML}{FFFFFF}  % stays FFFFFF in the pdf
\definecolor{Cool}{HTML}{FF0000}  % becomes ED1C24 in the pdf
\definecolor{SlightlyCool}{HTML}{00FF00}  % becomes 00A650 in the pdf
\definecolor{Comfortable}{HTML}{0000FF}  % becomes 2E3192 in the pdf
%\definecolor{Comfortable}{RGB}{00, 00, 255}  % no difference so the method to define the colors should be fine


\begin{document}

\background{ % Set the background to an image (background.pdf)
\begin{tikzpicture}[remember picture,overlay]
\draw (current page.north west)+(-2em,2em) node[anchor=north west]
%{\includegraphics[height=0.0852\textheight, width=0.9842\textwidth]{backgroundBlau}};  % 0.968
{ };
\end{tikzpicture}
}

\begin{poster}{
grid=false,
borderColor=Cold, % Border color of content boxes
headerColorOne=Cold, % Background color for the header in the content boxes (left side)
headerColorTwo=Cold, % Background color for the header in the content boxes (right side)
headerFontColor=Comfortable, % Text color for the header text in the content boxes
boxColorOne=white, % Background color for the content in the content boxes
headerfont=\Large\sf\bf, % Font modifiers for the text in the content box headers
textborder=rectangle,
background=user,
headerborder=open, % Change to closed for a line under the content box headers
boxshade=plain
}
{}
%
{\sf\bf \textsmaller[1]{\textcolor{white}{ text }}} % Poster title
{\vspace{0.1em} text \\ % Author names
{\smaller text }} % Author email addresses
%{\includegraphics[scale=0.55]{Uni_Logo-Grundversion_E1_A4_CMYK}} % University/lab logo

\headerbox{Introduction}{name=introduction,column=0,row=0}{

\textsmaller[1]{
\begin{center}
\begin{tabular}{|c|c|c|c|}
\hline
\rowcolor{Comfortable}\multicolumn{1}{|c|}{PET} & \multicolumn{1}{|c|}{eption} & \multicolumn{1}{|c|}{ Stress} & \multicolumn{1}{|c|}{Color} \\ \hline \hline
< 4 & ld & ress & \cellcolor{VeryCold}\\ \hline
4 - 8 & old & sts & \cellcolor{Cold} \\ \hline
8 - 13 & ol &  ss & \cellcolor{Cool} \\ \hline
13 - 18 & ool & s & \cellcolor{SlightlyCool} \\ \hline
18 - 23 & e & st & \cellcolor{Comfortable} \\ \hline
\hline
\end{tabular} 
\end{center}
}

}

\end{poster}
\end{document}

The colors in this test example should be black, white, red, green, blue. While white seem to stay white in the pdf, black is greyish and red, green and blue are way to dark. They seem to be changed during compilation.

I also tried specifying the test colors using RGB instead of HTML. As this had no effect on the color in the pdf (it was exactly the same wrong) I guess that they are specified correctly (furthermore they work well in the beamer class).
There seems to be some strange stuff happening only using baposter that changes my colors…

To give you a clue about the changed colors, I measured the colors in the pdf using the color selector in gimp, that returns the RGB value (in LaTeX called HTML) and added them as a comment behind the applied specification.

Any idea is highly appreciated!

Best Answer

This problem is corrected by ensuring that the colour model is explicitly declared in the preamble, using \setcolormodel{HTML}.

Although it does not appear to make a difference in this instance, the xcolor manual (table 2, p10) specifically instructs that colortbl should be passed as an option to xcolor. However, the baposter class loads xcolor, since it is based on pgf, so it is necessary to use \PassOptionsToPackage{table}{xcolor} before the declaration of the baposter document class. In the modified MWE below, I extended this to make provision for using colour names defined using dvipsnames and svgnames, thus: \PassOptionsToPackage{table,dvipsnames,svgnames}{xcolor}.

These two small modifications provide the correct colours, and the opportunity to use an extended range of color definitions - no need to hack the baposter class.

The code is:

\PassOptionsToPackage{table,dvipsnames,svgnames}{xcolor} %<-- Pass colortbl and defined colours to xcolor
\documentclass[a0paper,portrait]{baposter}
\usepackage{relsize} % Used for making text smaller in some places
%\usepackage{color, colortbl}  % define own fancy colours
\graphicspath{{figures/}} % Directory in which figures are stored

\selectcolormodel{HTML} %<-- Add colour model defintion
\definecolor{VeryCold}{HTML}{000000}  % becomes 231F20 in the pdf
\definecolor{Cold}{HTML}{FFFFFF}  % stays FFFFFF in the pdf
\definecolor{Cool}{HTML}{FF0000}  % becomes ED1C24 in the pdf
\definecolor{SlightlyCool}{HTML}{00FF00}  % becomes 00A650 in the pdf
\definecolor{Comfortable}{HTML}{0000FF}  % becomes 2E3192 in the pdf
%\definecolor{Comfortable}{RGB}{00, 00, 255}  % no difference so the method to define the colors should be fine


\begin{document}

\background{ % Set the background to an image (background.pdf)
\begin{tikzpicture}[remember picture,overlay]
\draw (current page.north west)+(-2em,2em) node[anchor=north west]
%{\includegraphics[height=0.0852\textheight, width=0.9842\textwidth]{backgroundBlau}};  % 0.968
{ };
\end{tikzpicture}
}

\begin{poster}{
grid=false,
borderColor=Cold, % Border color of content boxes
headerColorOne=Cold, % Background color for the header in the content boxes (left side)
headerColorTwo=Cold, % Background color for the header in the content boxes (right side)
headerFontColor=Comfortable, % Text color for the header text in the content boxes
boxColorOne=white, % Background color for the content in the content boxes
headerfont=\Large\sf\bf, % Font modifiers for the text in the content box headers
textborder=rectangle,
background=user,
headerborder=open, % Change to closed for a line under the content box headers
boxshade=plain
}
{}
%
{\sf\bf \textsmaller[1]{\textcolor{white}{ text }}} % Poster title
{\vspace{0.1em} text \\ % Author names
{\smaller text }} % Author email addresses
%{\includegraphics[scale=0.55]{Uni_Logo-Grundversion_E1_A4_CMYK}} % University/lab logo

\headerbox{Introduction}{name=introduction,column=0,row=0}{

\textsmaller[1]{
\begin{center}
\begin{tabular}{|c|c|c|c|}
\hline
\rowcolor{Cold}\multicolumn{1}{|c|}{PET} & \multicolumn{1}{|c|}{eption} & \multicolumn{1}{|c|}{ Stress} & \multicolumn{1}{|c|}{Color} \\ \hline \hline
< 4 & ld & ress & \cellcolor{VeryCold}\\ \hline
4 - 8 & old & sts & \cellcolor{Cold} \\ \hline
8 - 13 & ol &  ss & \cellcolor{Cool} \\ \hline
13 - 18 & ool & s & \cellcolor{SlightlyCool} \\ \hline
18 - 23 & e & st & \cellcolor{Comfortable} \\ \hline
\hline
\end{tabular} 
\end{center}
}

}

\end{poster}
\end{document}

A couple of brief off-topic points: \headerbox was replaced by \posterbox since 2011, although backwards compatibility still allows it to be used. I was surprised to discover in my testing that the correct colours were also enabled by \selectcolormodel{rgb}, even when the colours were specified in HTML. I guess this is related to xcolor converting HTML to rgb.

Related Solutions

[Tex/LaTex] How to force tikz to use CMYK everywhere (also in shadings)

Unfortunately, the requested feature is unsupported.

In general, your approach works fine: if you write

\usepackage[cmyk]{xcolor}

all color definitions result in cmyk colors. But shadings are special: they are not based on xcolor's drivers but on pgf's drivers. And the pgf drivers for shadings supports RGB, nothing else. I believe that pgf calls colorspace conversion routines in order to convert from cmyk back to RGB whenever it generates shadings.

What you need is a feature request for PGF in order to respect the global xcolor configuration and to generate shadings in that color space.

There may be work-arounds. These, however, depend on the urgency - if you say that you will file feature requests and will live with the restriction, that is fine.

If you really need a workaround, you can continue reading.

The work-around that I have in mind is to use pgfplots. It has a couple of plot-related shadings and comes with its own related drivers. These, in turn, support cmyk - and most shadings can be expressed as plot-based shadings. The effort to convert these shadings from tikz pictures which have a super embedding into your pictures to pgfplots plots would be medium.

Here is an attempt in this direction:

\pdfcompresslevel=0
\documentclass{minimal}

%%% uncomment to use CMYK
\usepackage[cmyk]{xcolor}
\definecolor{mygreen}{cmyk}{1,0,0.57,0.42} 

\usepackage{pgfplots}
\pgfplotsset{compat=1.8}

%%% uncomment to use RGB
% \usepackage[rgb]{xcolor}
% \definecolor{mygreen}{HTML}{009440}

\usepackage{tikz}


\begin{document}

\color{mygreen}{MY TEXT}

\tikz 
  \shade [left color=mygreen,right color=mygreen] 
  (1,1) rectangle (2,2);
%
\tikz 
  \fill [mygreen] 
  (1,1) rectangle (2,2);

\begin{tikzpicture}
    % this statement is needed for pgfplots v1.8. 
    % pgfplots 1.9 or newer inherits it from
    % \usepackage[cmyk]{xcolor}:
    \pgfplotsset{mesh/colorspace explicit color output=cmyk}

    \begin{axis}[
        x=1cm,y=1cm,
        hide axis,
        view={0}{90}]
    \addplot[surf,mesh/color input=explicit,shader=interp] 
    table[meta=cdata] {
        x y cdata
        1 1 color=mygreen
        2 1 color=yellow

        1 2 color=mygreen
        2 2 color=yellow
    };
    \end{axis}
\end{tikzpicture}
\end{document}

enter image description here

It relies on a surface plot with explicit color using the rectangular coordinates (1cm,1cm) (2cm,2cm) and the colors are listed in the table. The verbose syntax color=<name> is necessary to distinguish from something like 0,0,1 or gray=0.5.

[Tex/LaTex] Changing colors of included cthek jpg

Old question but as I just saw it:

A low-level solution seems to be possible. If one use the colorspace keyword the default /Decode array is not inserted and one can add it manually:

\documentclass{article}
\usepackage{graphicx}
\begin{document}
\immediate\pdfobj { /DeviceCMYK }
\edef\deviceobjnum{\pdflastobj}
\leavevmode
\pdfximage width 100pt attr{/Decode [1 1 0 0 1 0 0.2 0.4]} 
           colorspace \deviceobjnum
          {example-image-cmyk.jpg}
\pdfrefximage \pdflastximage\quad
\pdfximage width 100pt attr{/Decode [1 1 0.5 0.5 1 0 0.2 0.4]}
           colorspace \deviceobjnum
          {example-image-cmyk.jpg}
\pdfrefximage \pdflastximage


\end{document}

Best Answer

Related Solutions

[Tex/LaTex] How to force tikz to use CMYK everywhere (also in shadings)

[Tex/LaTex] Changing colors of included cthek jpg

Related Question