[Andrew Veggian]

It has a lot of potential uses, just keep it in mind. Here are a few ideas:

If you have a new site plan with lines in black, and the existing site plan as a grey background you can easily remove the background by changing the grey to no color. This could give you a clean drawing that is easier to read.

Sometimes engineers will print their CAD drawings with all the colors turned on. You can change all those colors to grey or black to give you a clean greyscale drawing.