[XeTeX] Colour specials for XeTeX

[Philip Taylor]

David Carlisle wrote:

>
> Phil wrote 'However, it would seem that while the "xdv2pdf" driver was happy with \special {color push}, the "xdvipdfmx" driver is not. '
>
> I doubt that ever worked, the semantics of "push" on any stack mean you have to say what you are putting on the stack, unlike pop where you just take off the top element (or underflow)

I had assumed (perhaps wrongly) that "\special {color push}" would push the /current/  colour onto the stack, thus allowing one to subsequently execute \special {color cmyk . . . .} non-destructively because the previous colour had been saved on the stack and could therefore be restored ("popped") therefrom ...

> I don't suppose you count the most reliable documentation?
>
> https://github.com/TeX-Live/texlive-source/blob/trunk/texk/dvipdfm-x/spc_color.c#L167

Er, no.  I neither read nor write C.  I was looking for something written in English, or at least in a natural language.
** Phil.