Canada still uses colored airways, as does Alaska.
Look at an Alaska/Canada enroute chart and you will see plenty of
examples. They're typically based off of NDB equipment.

Before the advent of VARs and VORs, all airways in the Lower 48 were
Red, Green, Blue or Amber, followed by a number. IIRC, Green and
Amber were north-south, Red and Blue were east-west.

In those days, the airways were defined by Adcock A-N ranges.

vince norris