[Xy-pic] Default color model

Ross Moore ross.moore at mq.edu.au
Mon Aug 2 21:49:09 CEST 2010

```Hi Vadim,

> Dear all,
>
> Is it possible to set the default color model to "gray" (specifically
> for the arrows, which appear, AFAICS, in "rgb")?  I use dvips driver.

Why do you need this?

Once before I had to do this, since a publisher objected to having RGB in the PDF.
Is yours a similar problem?

It was necessary to edit the PostScript dictionary file that is imported by dvips, changing a single specification of '0 0 0 setrgb' to '1 setgray'.
Xy-pic has a command \dumpPSdict which gives a local copy of the PostScript dictionary, which you can then edit for the next run (with the \dump... command now commented). Consult the Xy-pic Reference Manual, for information about the PostScript drivers and back-end support.

>