Methods for color coding / engraving tools?

A friend  introduced me to this rather clever method for color coding wrenches:

https://www.sheldonbrown.com/colorcode.html

We probably don't use quite as many sizes as they do in the cycling world (can't remember the last time I used a 16mm wrench) but I like the thinking behind the method.

What method do you guys use to tag your tools for quick identification?

I paint the wrenches I use the most and buy more of them.....

So with aircooled VWs you want a good selection of 10mm and 13mm ( 14mm if early bugs)  , long ones , short ones , bent ones etc , 

aircooled Vws have no 16mm and 18mm so they are in the bottom of the box if I even have any , 

and I put the SAE wrenches in another box ,