I have eated red jello the day before I am sheduled to go for a colonoscopy. Should I cancel my colonoscopy and reshedule for another time?

Don't Cancel. There is no need to cancel the colonoscopy. Just continue the prep and stay on clear liquids the rest of the day. Make sure you just let your gastroenterologist know that you ate red jello so they don't think it is blood if they actually see it. But in reality, that red jello should be long gone by the time you complete your prep.