Jovan Kirovski scored on a penalty kick in first-half stoppage time for the Rapids. Arnaud then answered in the 58th minute with assists from Eddie Johnson and Kerry Zavagnin.
Kansas City (4-2-1) avoided a second straight loss and picked up a key point, although it fell into third place in the Eastern Division. New England and New York won Saturday and are first and second, respectively.
Colorado (3-2-3) was coming off a big 1-0 win at New York last Sunday but couldn't build off the momentum and sits in second in the Western Division. FC Dallas is one point ahead of the Rapids.