The new hit Warner Brothers television series Felicity has a Colby influence.     Scott Foley, who stars as Noel, Felicity's love interest, patterns his character after his brother, Sean Foley, a Colby senior. Scott told the Daily Dish, an online entertainment site, that his brother, a resident advisor in Mitchell Hall, provides the inspiration for Noel, an R.A. at the fictional University of New York. "Sean has been an R.A. for years," Scott said. "I used his mannerisms, his speech patterns ... all that stuff helps me become Noel."      So far Scott has not consulted Sean about the intricacies of life as an R.A. Nevertheless, Sean says, big brother is doing okay with the role. "His character seems to care about the students in his hall. I think he's doing a good job."     Sean says he has taken some good-natured teasing about his brother's appearance in the show, but he is enjoying Scott's success. "I'm excited about it, my family is excited about it and my friends are excited about it," he said.