Color coding can be used to significantly improve organization. One way I use color coding is to assign one color to each class. That color scheme is used for digital and paper schedules, for digital and non-digital documents and folders, etc. It makes quickly finding or filing documents incredibly easy.
I have another color scheme for marking up documents in DP English A Language and Literature. Each type of context (cultural, social, historical) is assigned a particular color. Stylistic features are given another color. As a result, students can easily distinguish important elements of a text.
Color coding can also be use to annotate TOK essays. Knowledge questions / knowledge claims could be given one color, counter claims another, as well as one for real life examples and different perspectives etc.
Some people use color coding for scheduling – e.g. something marked in red needs to be completed that day, yellow must be taken care of within the week, and green tasks have to be done by the end of the month.