The tobacco in Green Leaf Cigars, a.k.a. Candela Cigars, is baked instead of fermented, which retains the natural green of the leaf.
For about 3 days, the tobacco leaf is hung in a barn and is cooked with high-temperature fires on the ground. This cooks out the same compounds that normal fermentation does, except it leaves behind the chlorophyll, where the cigar gets its green color. The fast process allows manufacturers to supply the masses more efficiently.