Preheat oven to 425°F and line a sheet pan with parchment paper or lightly grease it.
Toss bell peppers and onions with 1 tablespoon olive oil, chili powder, cumin, garlic powder, paprika, and half the salt. Spread on the sheet pan.
Roast vegetables for 12 minutes until they begin to char at the edges.
Meanwhile, toss shrimp with remaining olive oil and salt.
Remove pan from oven, push vegetables to the sides, and add shrimp to the center of the pan.
Return to oven and cook for 6-8 minutes until shrimp are pink and cooked through.
Squeeze lime juice over everything and serve with lime wedges and tortillas if desired.