Preheat the oven to 425 degrees and line a large baking sheet with parchment paper or foil.
Place the sliced chicken, bell peppers, and red onion in a large mixing bowl.
Drizzle the olive oil over the chicken and vegetables, then sprinkle in the chili powder, cumin, smoked paprika, garlic powder, salt, and black pepper.
Toss everything until the chicken and vegetables are evenly coated with the oil and spices.
Spread the mixture in a single layer on the prepared baking sheet.
Bake for 20 to 25 minutes, stirring once halfway through, until the chicken is cooked through and the vegetables are tender.
Remove the pan from the oven and drizzle the lime juice over the hot chicken and vegetables.
Warm the whole wheat tortillas and serve them alongside the sheet pan mixture, adding chopped cilantro if desired.