Peel the rainbow carrots and trim off the ends. Slice them into 1/2-inch thick sticks or batons, aiming for roughly the same size so they cook evenly. If the carrots are very thin, simply halve them lengthwise or keep them whole and plan to reduce the cook time slightly.

Preheat the air fryer to 380°F (193°C) for 3–5 minutes. If your air fryer does not have a preheat function, run it empty at 380°F for a few minutes.

In a large mixing bowl, combine the carrot sticks with olive oil, kosher salt, black pepper, garlic powder, Italian seasoning, smoked paprika, and onion powder. Toss very well until every piece is evenly coated, scraping the bottom of the bowl so no seasoning is left behind.

Place the seasoned carrots in the air fryer basket in a single layer or as close as possible. A little overlap is fine, but avoid overcrowding, which will steam the carrots instead of crisping them. If needed, cook in two batches.

Air fry at 380°F (193°C) for 12–16 minutes, shaking the basket halfway through cooking. Begin checking at about 10 minutes. The carrots are done when they are tender all the way through with caramelized edges and some browned spots. Thinner pieces may become a bit crispy.

Transfer the hot carrots back to the mixing bowl. Add 1–2 teaspoons of fresh lemon juice and toss to coat. Taste and adjust seasoning with more salt or pepper if needed. Sprinkle with chopped fresh parsley.

For a lightly glazed version, drizzle the hot carrots with 1–2 teaspoons honey or maple syrup and toss so it clings to the crispy edges. For a cheesy finish, sprinkle grated Parmesan over the hot carrots so it melts slightly and adheres.

Serve the air fried rainbow carrots right away with extra lemon wedges if desired. They pair well with roasted chicken, fish, pork, or plant-based mains, and leftovers can be enjoyed cold over salads or grain bowls.