You can substitute one type of pepper for another, including one type or color of sweet pepper for another, or you can substitute hot/chile peppers for sweet peppers and vice versa. You can also use a mixture of different types of peppers, as long as the total amount is no more than what is listed in the recipe. What you CAN'T do is substitute a different type of vegetable (onions, for example) for peppers.

I agree. It's perfectly fine to mix and match your peppers so long as the quantity of peppers stays the same.

Thank you both!