This script takes one set of objects and applies their colours randomly to another set.
The idea is that the document therefore has a unified feel without having to load swatches, and you can keep running it to get the random mix you want.
It has some options - such as taking each stroke/fill as a pair, swapping stroke/fill colours ....

It plays well after using the Objects on Paths script where there are lots of shapes to colour.

As always, please advise errors etc.