X-4 option of PDFX does not show hyperlink color with the PDF/X option (x-4)

Question

It is indicated in the pdfx manual

To produce a validating PDF/X document,pdfx overrides internal macros while keeping colors associated with link anchors.

I can see the same claim in the answer here: pdfx - package leads to non-working hyperref links

But my minimal example (Luatex 2018) shows that any link is printed only in the surrounding colors.

\documentclass{article}
\usepackage[x-4]{pdfx} %option x-4 for print, a-1b for archive (also display)

%\usepackage{hyperref}, it is already included by pdfx
\hypersetup{ colorlinks, allcolors=blue}%

\begin{document}

\section{First}\label{first_section}

Check \ref{second_section} (it should be in {\color{blue}blue}).\\{\color{blue} Check \ref{second_section} (it just follows the surrounding color)}.

\section{Second}\label{second_section} 

\end{document}

If I change

\usepackage[x-4]{pdfx} 

to

\usepackage[a-1b]{pdfx} 

the blue link color (in the first line) appears again.

I have also used a CMYK color instead of blue, but no success:

\definecolor{amGrayCMYK}{cmyk}{0.45,0.34,0.34,0}

Any idea how to keep hyperref link colors (not the functionality) in PDF/X output?

Answer 1

pdfx with x-a loads hyperref with the option draft and this disables the link colors. There is no user level setting to get them back. You will either have to redefine \ref to add the colors, or redefine internal hyperref commands:

\documentclass{article}
\usepackage[x-4]{pdfx} %option x-4 for print, a-1b for archive (also display)
\hypersetup{colorlinks, allcolors=blue}%
\makeatletter
\AtBeginDocument{%
\def\hyper@link@[#1]#2#3#4{\textcolor{\@linkcolor}{#4}\Hy@xspace@end}%
}

\begin{document}


\section{First}\label{first_section}

Check \ref{second_section} (it should be in {\color{blue}blue}).\\{\color{blue} Check \ref{second_section} (it just follows the surrounding color)}.

\section{Second}\label{second_section}

\end{document}