You should be simply following the instruction. Even if its not in the instruction, always use color copies for any application which is easier for them review since stamps would be in different colour and will show that its authentic but its difficult to predict/confirm if its black and white.
Get it printed from outside as not everyone has printer at home. Its better to deal with cic at first time correctly to avoid document requests later which delays your application further.
Whenever they issue request of documents after test, they are again asking colour copies. So send only color copies of any support/additional documents.
https://www.canada.ca/en/immigratio...der-subsection-5-1-adults-18-years-older.html
"colour photocopy of all pages (valid or expired) of your passport(s) "