In article .com,
wrote:

We have an HP 8150 DN printer (with 4 input and 3 output trays). The
intention is to have a separator sheet (on colored paper from tray 2)
to precede jobs (white, letter-sized paper from the high-capacity tray
4). We want the separator + output to come out on the high-capacity
stacker (on the lower left). We can't force the separator sheet to come
out on that tray - depending on which PCL options we use - the colored
sheet comes out in the top bin/tray, or the upper left bin - never to
the lower left bin.

Hugh-

I don't know the answer to your specific question. Another approach might
be to use the printer's control panel to specify a different "kind" of
paper in the color-paper tray.

For example, if you normally had plain paper selected for most of your
trays, but specified "recycle" paper for the color-paper tray, the only
time (and every time) a color sheet would be used, would be when you
printed a sheet of recycled paper. There may be other choices, but
recycle is the one that gave me a fit when it had been accidentally
specified!

Fred