Introduced when the cruise line had only a handful of ships. (i.e.) Red, Yellow, Blue, Purple, Yellow, Green, Peach and Orange. The inlays are called "skies" Yours is an Orange Sky $1 -- the most common of the lot. Rare ones are white, yellow, blue and purple. They were like that so chips could be used on all Carnival ships. Now, Carnival uses the ship's name on all their chips like Carnival Magic, Carnival Valor, etc. Hope this helps.