HP PCL/PJL reference (PCL 5 Color) - Technical Reference Manual

EN Using Palettes (Color LaserJet, 5, 5M, DeskJet) C-7
This command can be used to de-select the active palette and select
as the new active palette a palette created by the Palette Control
command (
?&p#C). For example, to copy the active palette to an ID
of 44 and select the new palette to use or modify, send
?&p44i6c44S.
When a palette creation command is received such as Configure
Image Data (
?*v#W), Simple Color (?*r#U), or an HP-GL/2 IN, the
created palette overwrites the active palette and is assigned the
current palette select ID, which is unchanged.
A palette popped from the stack overwrites the active palette, and is
assigned the current palette select ID, which is unchanged.
?E resets the palette select ID value to 0 and deletes all palettes in
the palette stack and palette store, including the active palette which
is replaced by a default PCL fixed black and white palette with a
palette select ID value of 0.
Macros affect the palette select ID value as follows:
Calling or Overlaying a macro—saves the ID value and a copy
of the active palette. Upon macro exit, the restored palette
again becomes the active palette with the restored ID. An
existing palette with this ID is deleted.
Executing a macro—does not save the ID value or the active
palette; changes remain in effect.