I'd call it not an error but a process defect. Should have been thrown out by an inspector.

However, with the two-color mix, and the fact that these were made for a chip dealer and not a casino, anything goes. They will make them with barber-pole colors or only one side filled if you ask for it. Dealer is paying for the chip, which is modern. Trocadero closed many years ago, but was the site of a chip show about 10 years ago where these chips were given out or sold.

I think they have the value of any piece of memorabilia. If you were there, they might be worth 5-10 dollars. Otherwise, a dollaar or so.