Chop kale, onions, red bell pepper, and 2 carrots. Toss all into a food processor, along with the garlic; pulse a few times until everything is broken down into smaller pieces.
Add remaining ingredients to the food processor and blend until smooth.
Pour mixture into a dish, cover, and refrigerate for at least 2 hours.
Slice cucumber and yellow bell pepper; cut 4 carrots and the celery stalks into sticks.