The following graphic below contains all 120 coloured pencils, grouped by hue and then sorted inside the group by chroma. Complementary hue groups are opposite to each other. The dark bar indicates chroma.
If you want to sort your 120 box of Polychromos and keep it sorted, you can download and print the paper stripes. They can be laid into the deepening in the middle of each pencil board level, if you then pick one, you always see where to put it back, as in the photo below.
Created by Simon A. Eugster in February 2015 (and updated since). Thanks to: