Short answer:

• Capsicum (bell pepper): Generally allowed during Paryushan because it is a non-root, non-leafy vegetable. Use in simple, non‑spicy preparations, and only if your local maryada permits vegetables these days.
• Jalapeño/green chilies: Commonly avoided during Paryushan. They are very pungent (stimulate rāga–dveṣa) and many maryadas restrict fresh green chilies and sharp spices in these days.

Important notes:

• If your sangh follows “no fresh vegetables” on all Paryushan days (or at least on Samvatsari), then both capsicum and jalapeño should be avoided.
• Both traditions (Shvetāmbara Paryushan and Digambara Das‑Lakshan) keep food very simple: no roots, no leafy greens, no fermentation, boiled/filtered water only by daylight, and minimal spices. When in doubt, abstain.

For simple, tradition‑aligned food lists:

• Food items allowed in Paryushan
• What all foods are allowed in Paryushan