Complied by Allan - 10-July-2005
In a CAD system, colors are most commonly used to represent line weights. Selecting different colors is just like picking up pens with varying line thickness. We then tie these colors into layers to control the visibility of drawing components.
There are no right and wrong coloring systems — but there are some that have become more prevalent than others. Drafting managed quite well for centuries before CAD came onto the scene. It's hardly surprising then that the most common color system has its roots in a well-established manual drafting system. Many offices have adopted the ISO/DIN line weight color coding system commonly seen in the identification the bands of drafting pens as follows:
Changes to this system have, in the main, come about as a result of preference for light or dark screen background within CAD. Naturally, yellow doesn't work well on a light background and brown's difficult to see on a dark background.
AutoCAD Tip — Use the OPTIONS or PREFERENCES commands to change the background color
The system above is simple and it works but, with 256 colors to choose from, many companies adopt more complex systems that allocate groups of colors to line weights.