I'm sure that just like any 1980s fiber optics lamp/fixture, it was just a color wheel spinning under a bright light that caused the 'patterns' of light on the pavers. I would bet large sums they weren't programmable pixels.Do you think the ones installed in EPCOT decades ago are still available? I think not. The ones that were in EPCOT were probably over engineered to last.
Though, now, they could be.
Double though, I'm not sure how optic fiber pavers stand up to power washers.