The pigment is called Anthocyanin. it may appear as red, blue and anything in between, depending on the pH. it has many purposes, but it is mainly present as a type of natural "sun screen", protecting the plant from far-end blue and ultra-violet light - the light responsible for causing burns on the leaves. the tendency of producing this pigment is genetic, and even though most chiles produce it in some levels as a reaction to far-end blue light, some produce it in much higher levels and as a respond to much less light. a good example is the Black Pearl shown above. the concentrations of the Anthocyanin are so high that it almost appear is black. the production of Anthocyanin is in all of the plant's "green" parts, including the fruits. Anthocyanin is also an antioxidant and therefor as some beneficial qualities at consumption.Thanks Inca, they will be outside as soon as they grow up a bit. My fault, I wasn't specific enough though on my Q.....
Why is the pepper plant black to begin with? Does it contAin more or less of chemical "X" or gene "Y"?