When opening my tool box, I was constantly getting confused if a wrench rack contained English or Metric wrenches. To solve this problem, I marked the English wrench racks with red electrical tape and the Metric wrench racks with blue electrical tape. This color code is the same one used to mark and identify wrenches and sockets.
Some racks were already red or blue – I just made sure that the color matched the type of wrenches (English/Metric). Can also use this method to identify socket racks.
(This is one of those ideas where I wondered “What took me so long to figure this out?”.)