Black cats have had a bad reputation since the 12th and 13th centuries. The European superstition relating black cats and witches crossed to America. During the time when women suspected of being witches were burnt many black cats were burned along the "witches". Read more about black cats in our article - Celebrating Black Cat Appreciation Day on August 17th
For all those reasons, please keep your cats indoors during October. Your neighbors might be wonderful but the traffic of strangers around Halloween increases. This makes it unsafe for cats to be outside, specially gentle cats who do not fear humans.
On Halloween night you might want to keep your cats in a quiet room to avoid the constant visits and ringing. Even the quietest and most social cat becomes upset with so much traffic, costumes and excitement.