Always make sure you check the label of the chili powder you intend to use to know if it will work for your recipe. I also advise reducing the amount of any of the ingredients included in the spice blend to avoid serving overly seasoned dishes.
Compared to other substitutes in this list, bell peppers are generally sweet, mild, and tangy which somewhat fits the description of sweet paprika. When using this as a backup, note that your dish will have an intriguing yet bright flavor profile that better suits pasta, chicken, salads, and soup recipes. To add to its impressive list of qualities, it’s also incredibly aromatic that adds overall allure to the dish.
I highly advise that you gradually add the powdered or crushed red pepper flakes to your recipe. Start with one-third of a teaspoon for every teaspoon of paprika. Give it a taste to check the heat and spiciness, and add more when needed.
In terms of nutritional value, both paprika and bell peppers are rich in vitamins and antioxidants, but bell peppers have a higher water content and are lower in calories.
Best for just about anything.