Sweet and Sour Veggies

From: AllRecipes

This is very easy to prepare and can be made
   the night before serving. You can use just about any fresh
   veggies. Prep Time: approx. 10 Minutes. Cook Time: approx. 2
   Minutes. Ready in: approx. 12 Minutes. Makes 6 servings.

1/2 cup water
1 cup white sugar
1/2 cup red wine vinegar
1 tablespoon celery seed
1 small red onion, thinly sliced

2 large cucumbers, chopped
6 roma (plum) tomatoes, sliced
1 green bell pepper, diced
1 red bell pepper, diced

Directions
1 In a saucepan over medium heat, combine the water,
   sugar, vinegar and celery seed. Stir until dissolved.
2 In a medium-size mixing bowl, layer the red onion,
   cucumber, tomatoes, green bell pepper and red bell pepper. Pour
   sugar mixture over vegetables, cover and refrigerate
   overnight. Serve chilled.