Why do or would Jalapeno chiles start turning black on the plant?

Question

I bought a plant at K-mart that said: "large, giant" jalapenos but they are little so I think they are not finished growing so I leave them on the plant to see if they get bigger but they just begin to turn black, have I just left them on too long?, it says direct sun on it, is the sun burning them?

Answer 1

If they are large (the right size for harvesting) then their skins blacken as a sign of ripeness.

Answer 2

not enough watter