Combine cucumbers, green/red pepper, onion, celery seed and salt in bowl; mix well.
Stir sugar into vinegar in small bowl until dissolved.
Pour over vegetables.
Chill, covered, in refrigerator overnight.
May store in refrigerator for 2 weeks.
(An optional first step is to mix the cuke slices with salt and allow the water to drain out for an hour. If this is done, it may be necessary to add an additional 2 tsps. of salt after draining. Using red peppers makes this a colorful dish).