Colored folders is one of the most basic methods used. In addition to a colored folder people have also used pieces of colored tape or dots to identify files, or special colored labels. For example, the red tape means this, the green tape means that, the blue folder is Dr. Smith's patient, the green dot is an old file, and so on. Many color coded systems work this way. However, you have to know the code in order to find something in the system or at least be referring to some sort of cross reference chart.
New personnel have to experience a learning period to familiarize themselves with the codes.
Depending on how the many codes there are and how complex they are, it could take several days to learn and use the system. There are several large filing systems that were created and dedicated to filing by using color. It was just this problem that lead to the creation of the Filemate Personal Filing System. By using Colored Color Bars attached to Colored Hanging Folders, with Colored Interior Folders, and Labels with Color Bands on them - the entire system is geared towards creating a filing system quickly and easily. A system based primarily on the use of Color.