When I open a folder in list view that may contain over 100 "Customer folders" I want to be able to immediately access an "active" job or find a commonly used folder quickly. color coding folders helps me do this.
To identify various jobs / projects
in my working folder inside documents:
gray - archives (long finished projects)
red - complete (red means stop. used for projects less than 6 months old)
yellow - on hold (not complete but not currently working)
green - current (green means go)
purple - sources
all the root project folders inside these folders are coded the same color; and i label the 'source' folder in each project folder purple as well