If
you want to print an object on all plates in the printing process,
including spot-color plates, you can convert it to a registration
color. Registration marks, trim marks, and page information
are automatically assigned registration colors.
Select the object.
In the Swatches panel, click the Registration color swatch , located
in the first row of swatches, by default.
To change the on‑screen appearance of the
registration color from the default black, use the Color panel.
The color you specify will be used for representing registration-colored
objects on the screen. These objects will always print as gray on composites
and as an equal tint of all inks in separations.