The short answer is no, but of course, it depends what your goals are. The beauty of the challenge is that YOU pick whatever fruits and vegetables you want to hit the 800-gram target.
I’ve (EC; creator of the #800gChallenge®) done the challenge for about 3 years, and I’ve taken data on lots of days. With mixed fruits and veggies, I usually average ~110g/carbs per ~900 grams (which ends up being <100 carbs if I stopped at 800g). This includes days with bananas, potatoes, or plantains, which are the most carb-dense items. Fruit is actually a lot less carb-dense or sugary than some in the blogosphere have suggested. See a couple of my example days below with gram and carbohydrate totals.
Targeting low carb items (e.g., greens, celery, cucumber) will be ~40g carbs and biasing high carb items (potatoes, bananas, yucca) will be ~200g carbs.
Check out all of these #800gChallenge® “personalities” and their carb counts.