A Democratic push to raise the minimum wage in Colorado notched an early success yesterday at the Capitol. A House committee approved a bill to allow local governments to set their own minimum wages in excess of the state minimum wage. Cities and counties are currently prohibited by law from doing that. Another bill heard yesterday would ask voters whether the wage should be raised gradually over the next five years. The ballot measure would set a wage of $9.50 starting in 2017, then going up a dollar an hour each year until the minimum wage is $12.50 an hour by the year 2020. About 200 minimum-wage workers and their supporters held a rally on the Capitol steps in advance of the hearings.