That would be a printer property.
Select the form. Click on File + Print.
Look though your printer properties to find a Black and white check
box.
Each printer is different so this is the closest I can come with an
answer.
Note: Forms are not designed for printing. Selecting a form for
printing and printing it will most likely print that form for each
record you have in the table that is the form's record source.
Although allowed, forms are really not for printing.
Create a report and print that instead.
If you just want to show the values for the current record, you can filter
your report to show only the current record on the form.