When delivering to retail businesses, it's not uncommon for delivery services to bring several packages to each stop. Each package has a label, with the recipient printed on it, generally with black ink on a white background. The delivery person has to look through the various packages, looking at
the text of the labels, to find what's supposed to be dropped off at each stop.
What, instead of black on white, the labels had different color backgrounds? All the boxes for the first stop would have labels printed in black ink on yellow, all the boxes for the second stop would have black ink on pink, all the boxes for the third stop would have black ink on blue (a light enough shade of blue to see the ink), etc..
The driver's paperwork, listing all the stops, and how many boxes need to go to each stop, would either be printed in matching colors, or would at least have the color name indicated.
If there are more than 7 stops (pink, orange, yellow, light green, light blue, light purple, white), labels for additional stops would have checkered backgrounds (e.g., black ink on yellow/pink checkers).