In a bowl, whisk together olive oil, red wine vinegar, cider vinegar, minced garlic, ground cumin, dried oregano, salt (optional), sugar, and ground red or cayenne pepper until well blended.

Add the rinsed and drained black beans, drained whole kernel corn, chopped red onion, and chopped sweet red pepper to the bowl.

Toss all ingredients together until well combined.

Cover the bowl tightly.

Chill in the refrigerator for at least 8 hours or overnight to allow flavors to meld.