According to Colleywood Carnival Glass, the following color is called Fenton Ambergina, a deep orange-red tone, and is among the rarest and most valuable.
Carnival glass is pressed glass with mineral or metallic salts added during the manufacturing process to create the iridescent rainbow of colors it comes in. Carnival glass gets its name from the fact that it was a common prize at carnivals from around 1907 to 1925.
Carnival glass was first produced in 1908 by the Fenton Art Glass Company using iridescent metallic salts poured onto hot glass during the production process.