Wash and slice the vegetables into thin, uniform pieces.

In a large pot, bring water to a boil and add the sliced carrots. Cook for about 5 minutes until slightly tender but still crisp.

Add the bell peppers, celery, and onion to the pot. Cook for an additional 2-3 minutes until all veggies are tender yet crisp.

Drain the vegetables and set them aside to cool.

In a mixing bowl, combine sugar, apple cider vinegar, vegetable oil, salt, pepper, and celery seed. Whisk until the sugar dissolves.

In a large mixing bowl, add the cooled vegetables and pour the dressing over them. Toss gently to coat the veggies evenly.

Cover the bowl with plastic wrap and refrigerate for at least 2 hours to allow the flavors to meld.

Once chilled, give the dish a gentle stir before serving.