This is one wrapper that is actually in reality both a color and a type of wrapper.
Almost despised now, this wrapper color was the most popular cigar for the better half of the 20th Century. Due to shortages, Candela wrappers have been very rare over the past 9-10 years. Sometimes referred to as AMS, or "American Market Selection," cigars due to their tremendous popularity in the United States from the late 1800s through the mid 20th century, Candela is basically a bright green wrapper color achieved by a process which traps the chlorophyll content of the leaf prior to fermentation.
The process is actually very complicated and delicate in nature. Read this article for a more in depth discussion on the curing process. Basically the leaves are slowly cooked to keep the green color which dries them out to a point of nearly crumbling, and are then slowly rehumidified for rolling.
Candelas are typically a very mild and smooth cigar results when this wrapper is used; although some have a little more body then a Connecticut wrapper. Several brands that are excellent representations of these wrappers are the Camacho Corojo Candela, Graycliff Emerald and Arturo Fuente Candelas. You can also check Aaron's side-by-side review of the Illusione 88 Candela vs Viaje White Label Project Candela.