Why have your chillies turned black?

Chillies can turn black due to several reasons, including environmental stress, such as extreme temperatures or humidity, which can cause the fruit to sunburn or suffer from fungal infections. Overwatering or poor drainage can lead to root rot, which may also affect the fruit's color. Additionally, certain pests or diseases can cause discoloration. It's important to assess the growing conditions and inspect the plants for any signs of pests or disease to determine the exact cause.