Ross Moore wrote:
Hi Philip.
On 20 Jun 2020, at 12:08 am, Philip Taylor
<p.tay...@hellenic-institute.uk
<mailto:p.tay...@hellenic-institute.uk>> wrote:
XeTeX does what is expected if one uses \special {background cmyk
0.83 0.82 0.21 0.60} and ships out pages in the normal way; however,
if \shipout is invoked directly, the shipped out boxes have a
transparent ground. How should the background colour of boxes which
will be shipped out directly be specified ?
You need to understand that “background color” is *not* a basic
concept in the PDF graphics model.
see the discussion at this link (and elsewhere), as shown in the image
below:
https://community.adobe.com/t5/acrobat/change-background-color-of-pdf-pages/td-p/8476774?page=1
OK, thank you for that information Ross. Clearly I was unaware of that,
but the discussion was not particularly helpful, especially those who
advocated using the Adobe Reader/Acrobat GUI to change the colour-scheme
to "accessible" ! But in most ways I am no wiser — I have still have no
idea why \special {background cmyk c.c m.m y.y k.k} can change the
colour of pages shipped out from the output routine but not via a direct
shipout. It is not as if \special {background cmyk c.c m.m y.y k.k} is
inserted as a part of the output routine — it is in mainline code. So,
why does it affect only pages that pass through the output routine ?
** Phil.
