Cook the whole wheat penne pasta according to package instructions until al dente. Drain and set aside.
In a small bowl, combine chili powder, ground cumin, smoked paprika, dried oregano, cayenne pepper, salt, and black pepper. Mix well to create the fajita seasoning.
Heat olive oil in a large skillet over medium-high heat. Add the sliced chicken breast and sprinkle half of the fajita seasoning over it. Cook for 5-6 minutes, stirring occasionally, until the chicken is cooked through and lightly browned. Remove chicken from the skillet and set aside.
In the same skillet, add the sliced onion, red, green, and yellow bell peppers. Sprinkle the remaining fajita seasoning over the vegetables. Cook for 5-7 minutes, stirring frequently, until the vegetables are tender-crisp.
Add the minced garlic to the skillet and cook for 1 minute until fragrant.
Return the cooked chicken to the skillet with the vegetables. Pour in the low sodium chicken broth and stir to combine. Cook for 2-3 minutes to allow the flavors to meld and the liquid to reduce slightly.
Remove the skillet from heat. Stir in the fat-free plain Greek yogurt and fresh lime juice until the sauce is creamy and well combined.
Add the cooked pasta to the skillet and toss everything together until evenly coated.
Sprinkle chopped fresh cilantro over the pasta and serve immediately.