[XeTeX] Colour specials for XeTeX

[Philip Taylor]

Philip Taylor wrote:

> Excellent, many thanks to Akira-san and David.  All now perfect. 

Well, perhaps I spoke too soon.  Havinf commented out the x:rulecolor specials and left in thecolor equivalents, I now see in the transcript :

> This is XeTeX, Version 3.14159265-2.6-0.999992 (TeX Live 2020/W32TeX) (preloaded format=xetex)
>
> restricted \write18 enabled.
>
> entering extended mode
>
> (./Hoi-An TA menu.tex (./Hoi-An TA menu.xlsx.tex omnivore omnivore omnivore
>
> omnivore omnivore omnivore vegan vegan vegan vegan vegan omnivore omnivore
>
> omnivore vegan vegan vegan omnivore omnivore omnivore omnivore omnivore vegan
>
> vegan vegan vegan vegan omnivore omnivore omnivore omnivore omnivore vegan
>
> omnivore omnivore omnivore vegan omnivore omnivore vegan vegan vegan omnivore
>
> omnivore omnivore omnivore vegan vegan omnivore omnivore vegan vegan vegan
>
> omnivore) [3] [6]stdin -> stdout
>
> [1
>
> xdvipdfmx:warning: Interpreting special command push (color) failed.
>
> xdvipdfmx:warning: >> at page="1" position="(280.364, -23.9104)" (in PDF)
>
> xdvipdfmx:warning: >> xxx "color push"
>
> xdvipdfmx:warning: Color stack underflow. Just ignore.
>
> xdvipdfmx:warning: Interpreting special command push (color) failed.
>
> xdvipdfmx:warning: >> at page="1" position="(561.127, -23.9104)" (in PDF)
>
> xdvipdfmx:warning: >> xxx "color push"
>
> xdvipdfmx:warning: Color stack underflow. Just ignore.
>
> ][2
>
> xdvipdfmx:warning: Interpreting special command push (color) failed.
>
> xdvipdfmx:warning: >> at page="2" position="(280.364, -23.9104)" (in PDF)
>
> xdvipdfmx:warning: >> xxx "color push"
>
> xdvipdfmx:warning: Color stack underflow. Just ignore.
>
> xdvipdfmx:warning: Trying to include PDF file with version (1.7), which is newer than current output PDF setting (1.5).
>
> xdvipdfmx:warning: Interpreting special command push (color) failed.
>
> xdvipdfmx:warning: >> at page="2" position="(561.127, -23.9104)" (in PDF)
>
> xdvipdfmx:warning: >> xxx "color push"
>
> xdvipdfmx:warning: Color stack underflow. Just ignore.
>
> ]
>
> 9248230 bytes written
>
> )
>
> Output written on Hoi-An TA menu.pdf (2 pages).
>
> Transcript written on Hoi-An TA menu.log.
>

The desired effect is achieved (a gold rule separating the page pairs of a tri-fold menu <https://www.dropbox.com/s/f7a9of3y5s5xdct/Hoi-An%20TA%20menu.pdf?dl=0>) but why the colour stack underflow diagnostics ?