Preheat the oven to 425°F (220°C).
In a large bowl, combine the baby potatoes, carrots, red bell pepper, and red onion.
Add 2 tablespoons of olive oil, 1/2 teaspoon of garlic powder, 1/2 teaspoon of dried thyme, 1/2 teaspoon of dried rosemary, 1/2 teaspoon of paprika, 1/2 teaspoon of salt, and 1/4 teaspoon of black pepper to the vegetables. Toss well to coat evenly.
Place the seasoned vegetables on a large sheet pan in a single layer.
In the same bowl, add the chicken thighs. Drizzle with the remaining 1 tablespoon of olive oil, 1/2 teaspoon garlic powder, 1/2 teaspoon dried thyme, 1/2 teaspoon dried rosemary, 1/2 teaspoon paprika, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Rub the seasoning all over the chicken thighs.
Arrange the seasoned chicken thighs skin-side up on top of the vegetables on the sheet pan.
Place the sheet pan in the preheated oven and roast for 35 to 40 minutes, or until the chicken reaches an internal temperature of 165°F (74°C) and the vegetables are tender and golden.
If desired, broil for 2-3 minutes at the end to crisp the chicken skin.
Remove from the oven and let rest for 5 minutes before serving.