SEVERANCE, Colorado — A 9-year-old boy has convinced the leaders of a small northern Colorado town to overturn a nearly century-old ban on snowball fights, and he already knows who his first target will be — his little brother. Dane Best, who lives in the often snow-swept town of Severance, presented his arguments at a town board meeting Monday night, and members voted unanimously to lift the ban. “I think it’s an outdated law,” Dane said in the lead-up to the meeting.