I’m sure the coloring could have been added after delivery. However I don’t see it, for the right price the red/blue would have been added before the finished product was sent. some ivory chips had metal slugs/tokens imbedded in the ivory. Most anything was possible.

By the way, I seem to recall Robert mentioning 695+/- chips. Why would there have been 700 chips when there are 6 denominations

Either way painting 1200 or 1400 faces with two colors is a job.