I substituted what I had on hand--
I used chicken breasts instead of thighs (which meant cooking them a bit longer), Golden Delicious instead of Granny Smith (not as tart, but still good), and extra green bell pepper instead of yellow bell peppers.
Not only did it taste good, it looked good, too! My mom and grandmother taught me that a colorful plate is a healthy plate, so this meets all requirements. Bon appetit!