Taking notes in different ink-colored pens is here referred to as multicolored notes. I had a teacher during my pre-university schooling who had mandated the maintenance of multicolored notes for his subject and the format he had specified was:
1) heading in red
2) underlining in black
3) content in blue
Regardless of the importance of the topic, this teacher had mandated the practice. And though I had not seen the importance of this practice, It was not until recently that i tried this art and was fascinated by its several benefits.
To begin with, notes taken in multicolored ink tends to look neat and well documented. It might seem as complete waste of time and resources to some reading this but trust me in several occasions this art is God-sent.
There were several occasions where I had come across classmates who had multicolored pens with them during engineering. Who seemed to be very good at switching the pens even as the teacher went ahead in the topic explanation. I had a practice of bringing just the blue colored pen to the class and for some reason, I lacked the enthusiasm to switch to multicolored note taking.
Recently how-ever when I had to attend a 5 day lecture some of which involved note taking, I got myself pens of color red, black and blue and tried to stick to the 3 rules mentioned above as much as possible, and to my amazement I found that:
1) I was suddenly concentrating a lot on the content, even though the topic was covered post lunch
2) The switching of pens meant that I had to concentrate on the pen switch as well as what was being covered, so there was little scope for boredom ( or the accompanied yawning).
3) There was not only the alertness to keep myself from writing with spelling mistakes, There was now an additional overhead of using the right colored pen for the right context, so i had to be extra aware.
4) I also realized that even though I have one of the less attractive hand-writings (~_^), people around me were amazed at the way I was frequently changing the color of my pen.
Additionally I realized that since I was using 3 pens now instead of one, the pen was likely to last much longer, thus reducing the overhead of me having to get a different pen when the one i had ran out of ink.
I even tried to switch the color of the pen between words in a sentence, where i wrote the normal text in blue while the keywords were in red. At some point, I decided to draw the block diagram with black ink while the text was in black, while the arrows were in red. I have tried several such combinations, like writing the bullets in red, important points surrounded by a black outline, leaving little red stars (*) at important points and so on. But the essence here is, I was adding a lot of context switch and it did not reduce my performance in taking notes, rather improved it.
As children, we are encouraged to recognize alphabets associating them with colored alphabet blocks as toys, but as we grow older, we get used to the bureaucracy and stick to the eye appealing blue colored pens. The problem begins right from schools where we are enforced to write in black pencils and this practice then changed to blue pens as we grow older.
These days the concept of multicolored writing has been adapted in writing computer programs as well, where we see that a text editor is able to color different parts of the code based on key word, indentation or context such as comments or system library derivatives.