spotxcolor Package

LaTeX: Modern Spot Color Support for the xcolor package

This package provides robust spot color (e.g., DIC, PANTONE) support for the xcolor package across all major TeX engines. It resolves structural PDF issues found in the legacy spotcolor package and provides full spot color output for all engines including dvipdfmx (which is not supported by the colorspace package).

• Supported major drivers: pdftex, luatex, dvipdfmx (including ptex/uptex), xetex

Features

• Native xcolor Integration: Use spot colors exactly like standard colors (\textcolor{DIC161s!50}{text}, \pagecolor{DIC161s}). All standard xcolor commands produce true PDF Separation color space operators on all engines.
• Universal Engine Compatibility: Fully supports pdfLaTeX, LuaLaTeX, XeLaTeX, and (u)pLaTeX + dvipdfmx.
• Advanced Graphics Support: Works flawlessly with complex TikZ and PGF environments. The package patches PGF driver macros and pattern primitives to emit true spot color PDF operators, fully supporting:
  • Fill and stroke separation (independent spot color operators for fill/stroke).
  • Uncolored patterns (patterns and patterns.meta) with spot color via [/Pattern [/Separation ...]] color spaces.
  • Fadings (transparency masks) and blend modes (e.g., multiply).
• Decorations: Seamlessly integrates with colortbl (zebra-striped tables) and tcolorbox (frames, backgrounds, shadows).
• pdfmanagement Compatibility: Automatically detects when pdfmanagement (l3pdf) is active (i.e., \DocumentMetadata{} is used). No manual configuration is needed — spot colors work transparently with both traditional and pdfmanagement-based workflows.

Limitations

• Shadings (gradients): PGF generates Shading dictionary objects with a hardcoded /DeviceRGB color space. The color values are frozen into the PDF object at creation time, so spotxcolor cannot intercept them.
• Non-proportional color mixes (e.g., DIC161s!80!black): These produce CMYK values that are not a simple scalar multiple of the base spot color, so they correctly fall back to CMYK.

See spotxcolor.pdf for a full feature/limitation summary table.

Requirements

• A modern TeX Live environment (requires an up-to-date expl3/l3kernel)
• xcolor and iftex packages

Installation

Copy spotxcolor.sty to your local TeX tree: $TEXMF/tex/latex/spotxcolor/

Usage

Load the spotxcolor package. It will automatically load xcolor and detect your engine driver.

\usepackage{spotxcolor}

% Define DIC 161
% \definespotcolor{<latex-name>}{<pdf-name>}{<cmyk-values>}
\definespotcolor{DIC161s}{DIC 161s*}{0, 0.64, 1, 0}

\begin{document}
\sffamily\bfseries
% All standard xcolor commands produce true spot color output:
\textcolor{DIC161s}{100\% Spot Color}
\textcolor{DIC161s!50}{50\% Tinted Spot Color}
\pagecolor{DIC161!10}

% Low-level command for direct PDF literal injection:
\SpotColor{DIC161s}{1.0}
This is 100% DIC 161.
\end{document}

Note for (u)pLaTeX users

If you compile your document with platex or uplatex and generate a PDF via dvipdfmx, you must specify the dvipdfmx driver option globally in your document class (e.g., \documentclass[dvipdfmx]{article}). Otherwise, modern expl3 and xcolor will default to the dvips driver, and the spot colors will not be generated correctly.

Backward Compatibility

You can easily reuse your existing code and color dictionaries written for the legacy spotcolor package. Commands like \AddSpotColor, \NewSpotColorSpace, and \SetPageColorSpace are perfectly emulated.

License

This package is licensed under the conditions of the LaTeX Project Public License, either version 1.3c of this license or any later version.

Munehiro Yamamoto https://github.com/munepi