It is a tall order to take physical notes on actual paper with a real pen. Most people I know don't do it despite the clear benefits. It more stuff to lug around, while your ever-ready phone offers literally hundreds of apps for speaking,drawing,and syncing notes,So considering the use of multiple pen colours for your notes can seem a bit like lugging a Victrola around for boring jog.But there are real,tested benefits to using multiple colours to stretch out your thoughts, take notes on meetings,and do your research on deeper topics colour improves recall time for graph and charts,and can be "a very effective performance factor",If not over done. just ask a mined mapping expert,and air force veteran now working at Oracle,or surprisingly attentive Cornell students.