Thanks to a tool made by Pontikue, I only need to do this once. The other models can be automatically rigged.
I'll still need to make some tweaks (scaling) to get the ropes to work with clothes, but other than that, it's looking good.
These are the default rope colours for the time being, but later on you'll be able to pick custom colours.
In fact, you'll be able to customize the colour of rope, tape, blindfolds, character skin colour and clothing colour.