how to study with 3 colors multipen there is a book ' how to study with 3 colors multipen' written by Saito takasi. he is well know for educator in japan and also is famous for his other books. i'd like to say one of his books. he say ,when we read a book, if we use underline with 3 colors, we can understand what authors say and think. According to his book, we can use green, blue, red color. First, We should feel free to use green color. we use green color when we find sentence which we just like. Easily, we paint all of paper with green color. you don't have to hesitate to use green color. Second, use blue color when you find a sentence which is important objectively. when you use blue color, you need to be more cautious than when using green color. Finally, underline with red color when you find most important sentence. everyone should agree it is really most important sentence when see the red colors. i don't know if it works. but i agree it can be active reading.