Red, green, yellow and orange (at least 3 colors). Bell peppers are also known as ""sweet peppers."" Many people consider them a vegetable, but they are technically a fruit. Bells are part of the Capsicum species. They are the only Capsicum that doesn't produce capsaicin. Capsaicin is the chemical in peppers that causes the spiciness. That is why bell peppers are referred to as sweet peppers, because they are sweet, not spicy.